[Repeater-Builder] Re: 6 Meter Repeater
Re: 6 Meter Repeater Charles Rader kc5...@... wrote: I am tossing around the idea of building a 6 meter repeater. This will have to be single site if I do this. What are you guys using for the repeater, duplexer, and antenna? In addition to the other radio brands and models listed by others, the Midland Syntech Low-Band Mobiles are relatively cheap and easy to use as both mobiles and repeaters. The Syntech 1 (and 2) mobiles will connect back-to-back for a nice repeater and you can cross band two radios for a split site. There's a Yahoo Group for Midland Radios and the repeater conversion information for the Syntech 1 radios is available for download from the files section (of that Group) Syntech 1 radios reprogram with an Eprom module, which must be erased and reprogrammed with the proper equipment. I've been offering free Syntech 1 Eprom Module Programming for years, you need only pay the US Mail Postage. Have a look at this Ebay Auction: Ebay Item Number: 260661249410 Midland 70-052C Syntech 42-50Mhz 80-Ch on 6m Amateur This radio is probably ready to go for regular use or adding the COR circuit to make it also work as a repeater receiver. Prices for used Midland Radios are all over the place... watch Ebay and your local Amateur Radio Swaps/Flea Markets. I've seen used Midland Syntech 1 Radios sell for anything from $5 each up to $99 (as seen in the mentioned Ebay Auction Listing). What's a working ready to go (or a relatively easy conversion project) 6M Radio worth to you? Antennas for 6 meters are relatively easy to deal with, I've even converted CB Radio Ground Plane Antennas over, but both home-brew and surplus commercial are out there if you dig around. You'll find a number of duplexer projects on the web. Keep in mind you can start out with vertical split antenna scheme and low power to get rolling. You'd be surprised how far 2 to 5 watts can go... I ran a split antenna low power 6M Repeater using two modified antennas and 45ft separation (600KHz offset). It was a lot of great hands on learning... and in theory no one gets hurt in the process. cheers, s.
[Repeater-Builder] Re: Micor UHF Sensivity
Sinad is done with a 1000 Hz tone at 3KHz deviation and requires a meter that can notch out the 1K tone and measure the remaining noise. 20dBQ is done with no modulation 2 Vac of sq noise w/ no carrier then generate unmodulated carrier till the ACVM indicates 0.2 Vac Both the above are different from a signal with voice energy (speech). I have measured different receiver performance values with various test audio frequencies with varied deviation and what might be the best for real world operation could and does sometimes vary from the results you obtain using the above listed methods. Proponets of the Sinad method claimed that their way of doing the alignment would actually improve the overall sensitivity since the radio was being tested while receiving audio. Which is why I only use Sinad as one tool in the final alignment procedure. A 1KHz tone is quite different than real voice band audio. cheers, s.
[Repeater-Builder] Metering with Digital and Analog Multi-Meters.
Metering with Digital and Analog Multi-Meters. Re: MSR-2000 Alignment Metering Mike Morris wa6i...@... wrote: I heard it on TV as If it works it must be a Fluke. I was quoting a friend from my old days at Motor-head (Moto) Service. Don't know where he (Jeff) got it from... Mine is a Fluke 73 type III. Should work fine on the MSR-2000 Micor metering points. I normally use an original Fluke 77 or 85 model. Fluke DMM's have never really given me a false value although many brands of DMM's including a number of Fluke models do sometimes freak out when looking at certain reactive loads... like some transformer windings, when trying to measure the DC resistance, which is why I also keep a trusty low cost dumb as a rock Analog Movement Multi-Meter standing by. What wording would you suggest? Don't run with scissors maybe? Advisory: Inexpensive lower cost Digital Multi-Meters can provide erratic or inaccurate meter test-point indications. I wrote that the way I did because I have always had better results with either a Moto test set or a analog VOM (i.e. Simpson 260 or Triplett 630). Mike Some of the fairly small value change metering-point measurements are a lot easier to identify with a Fluke (or any well designed) DMM using the milli-volt range position/scale. Especially during an initial from scratch default alignment. Your results should vary... cheers, s. Re: MSR-2000 Alignment Metering Probably looks a lot like the one at the top of the web page at http://www.repeater-builder.com/msr2000/msr2000-index.html There's an error on the above mentioned web page. In other words, YOU CANNOT USE A MODERN DVM TO PROPERLY TUNE AN MSR2000. I don't agree, in fact it's much easier for me to use my Fluke DMM to detect some of the very small meter peaks and dips. There is no rule or requirement the metering points have to be loaded by a 50uA movement. Erratic metering with low cost Digital Multi Meters is probably the result of the price you paid. If it's a good meter, it must be a Fluke. cheers, s.
[Repeater-Builder] Re: DB212-3 (Low-Band Antenna Systems)
Re: DB212-3 (Low-Band Antenna Systems) Hi Norm, NORM KNAPP nkn...@... wrote: Took down a set of DB212-3 dipoles in good shape with harness. I want to use them on 6m for a repeater antenna. I also want to add one additional dipole. I guess I will need to modify the harness and the dipoles as they are marked for 35.960 mhz If the loops are assembled with dimples in the metal, it's a bit of a pain to disassemble them for size reduction to 6 meters. I've also seen the same antenna assembled with rivets. 35.960 MHz up to 52 MHz is quite a distance... If you have a chance, please record the measurements of the original loops at 35.960 MHz... and the length of the coax phasing harness. I will be mounting all four (or 3) on one leg of a tower that is 4 feet on a face. Is it worth my while to go for the 4th dippole? The loops are 155 inches from tip to tip now. Looks like they need to be about 105 inches. Anyone with any tips, pointers or advise? Thanks As Kevin would say... the only free lunch regarding system gain is at or starting with the antenna. So an assumption would be to go for all the antenna gain you can muster. And there's something (often positive) to be said for the shear amount of antenna surface area. However, interference, noise and the site effective sensitivity are a side dish often served cold (often not very helpful to the system performance). Some juggling of the antenna system can be used to deal with really serious problems. You might first drag a single 52MHz dipole up to the repeater site and measure the effective sensitivity. cheers, s.
[Repeater-Builder] Re: Ariels (Antenna Motorbike)
Ariel? Antenna maybe? C'mon guys. Be careful Doug. The poster is from the United Kingdom, where they use the term Ariel, not Antenna. ... and for motorcycles http://en.wikipedia.org/wiki/Ariel_Square_Four Myself... I was also a Matchless and Triumph fan because of the funny Metric and Whitworth tools. Would an Antenna on an Ariel also be called a Double Ariel? :-) cheers, s.
[Repeater-Builder] Re: Pyramid VRS to Motorola X9000
mzfb2001 m...@... wrote: I am looking for imformation to make a cable to connect a Pyramid VRS to a Motorola Lowband X9000. The print out provided by Pyramid works but its keeps the Pyramid in constant transmit. Thanks for any help in advance Mike I just sorted this same mess out for a customer who had to have it done. A low-band Syntor with a Pyramid SVR-200. The Pyramid Unit duplicated the PAC-RT connections with the exception of the enable disable line, which were routed up to the control head through a redefined wire and pin. The wire was then internally jumpered (inside the control head) to the adjacent control head plug and then brought out to an external on/off switch. It will work and there's nothing special about hooking it up. I received the Syntor-Pyramid combination wired with an original PAC-RT cable setup (obviously modified to plug into the SVR-200). I had and used the original Syntor Manual information, which includes the PAC-RT cable routing. The only magic and dance was actually getting the on/off switch to work through the control cable and head up front at the operator and control head mount position. So, in short it would be handy to have the Syntor Book with the PAC-RT cable info included. In fact, handy is pretty much a must have the manual if you're flying without one. s.
[Repeater-Builder] Re: MSR-2000 Alignment Metering
Re: MSR-2000 Alignment Metering Probably looks a lot like the one at the top of the web page at http://www.repeater-builder.com/msr2000/msr2000-index.html There's an error on the above mentioned web page. In other words, YOU CANNOT USE A MODERN DVM TO PROPERLY TUNE AN MSR2000. I don't agree, in fact it's much easier for me to use my Fluke DMM to detect some of the very small meter peaks and dips. There is no rule or requirement the metering points have to be loaded by a 50uA movement. Erratic metering with low cost Digital Multi Meters is probably the result of the price you paid. If it's a good meter, it must be a Fluke. cheers, s.
[Repeater-Builder] DC Electrical Systems
Mike Morris wa6i...@... wrote: And actually the DC distribution system was more common than you think. So is live steam... In large cities like San Francisco you can still find utility supplied DC and steam. Most of the Hydro Plants I've ever worked in were operated off/from a very large bank of series connected station size lead-acid batteries. The plant can start under its own 120 Vdc bank of batteries if the grid source is unavailable. There's a lot of DC and Steam still out there... I recently was up at the Mt. Wilson observatory and was inside the 100-inch telescope dome. ALL of the controls for the telescope, the dome slit motors (the ones that slide the panel open the telescope to look through), the dome rotation motor (which is surprisingly small for the load), everything but the overhead lighting is 120v DC. And has been since about 1918. Even the ballast tubes for the control are original carbon filament bulbs. I have alot of photos/ Mike WA6ILQ At 02:13 AM 08/24/10, you wrote: We had our fill of those here, too. The hot side of the AC line (if you were lucky, polarized plugs were rare in those days) was connected directly to a 35W4 or some such half wave rectifier tube and later to a selenium half wave rectifier with the other side of the AC line being connected as the negative lead (fortunately NOT to the chassis). Usually, there were a couple of 0.01uf capacitors from each side of the line to the chassis, however. Doubt I need to explain the joys one could experience with that arrangement! And, to top it off, each and every one of those radios proudly bore our UL stamp of approval! They used to call them AC/DC radios because, if you lucked out and got the polarity right, the radio didn't care what the source was as long as it was somewhere near 100 volts DC or RMS. Tom --- In Repeater-Builder@yahoogroups.com, Gordon Cooper zl1kl@ wrote: Another quirk. Sixty plus years ago in England, power factor was not the main concern. Many of the domestic radio receivers were transformerless and used half-wave rectification to obtain D.C. for the tubes. A consequence was a fair dose of D.C. flowing in the street power mains. Gordon ZL1KL Tauranga N.Z. Yahoo! Groups Links
[Repeater-Builder] Re: DC Electrical Systems (AC DC Tube Radios)
Ralph S. Turk w7...@... wrote: When I worked for Westinghouse Intl in the 60's, we manufactured a special line of TV's, radios, and small appliances for DC sections of the world. Our main office was in New York City and we would get customers from areas in NYC, SF and some other cities I can not remember that only had 110VDC available. A lot of those old tube radios would operate on AC and DC and were often known as 5-tube AC DC Radios. The tube heaters were all in a series string. cheers, s.
[Repeater-Builder] Legacy Radios Still in Service
How much time has passed since RCA sold their last Land Mobile Radio? Check out Ebay Auction Listing: 370424289376 for a bit of history. It's an RCA Tac-200 radio with a Zetron Dial Access Paging Terminal DAPT 32 jr parked on it. A tip of the hat to RCA, Link, Aerotron, Repco, Neutec, Public Safety Systems, Wilson, Regency, Uniden, GE and the other legacy radios still kicking around... in service. cheers, s.
[Repeater-Builder] Re: Spectrum Comms SCR200A 220 receiver question
The trimmer caps should be easy to find at Jameco, Hamtronics, Digikey and Mouser. If you have nothing to lose, try a small amount of Caig Labs DeOxit first. s. Joe k1ike_m...@... wrote: I've been working on a clubs 223.96Mhz repeater that the receiver lost sensitivity. It went deaf, so much that the squelch would not even work. It appears that the plastic variable capacitors in the front end have gone bad. It was in a very damp water tank environment and this summer was just too much for it. Anyway, has anyone found a good ceramic replacement for the plastic caps that are a drop-in replacement for the plastic caps in a Spectrum receiver? I think I'm just going to change them all and be done with it. The caps in the 220 version of the receiver are 20 picofarads. The club has 5 more Spectrum receivers that will probably need cap replacement too, some on 2 meters, 440 and 220. I only want to do this once and make it an easy repair. If I found a good replacement part I'll buy a load of them in various sizes. It seems that there is a very low interest in repeater repair over the years. I get many requests for fixing repeaters, and I'm surprised that it is so hard get someone to even hold the flashlight. It's discouraging.I would like to see some interest for the future of repeaters and ham radio. Others experiencing this? The younger hams just don't seem to have the curiosity that I had years ago. 73, Joe, k1ike
[Repeater-Builder] Re: Motorola Diplex Antenna Manual
Re: Motorola Diplex Antenna Manual Scott Zimmerman wrote: I would LOVE to know some of the theory behind this method. I was hoping to use this on a remote base antenna with 'Station' type antennas, but I don't think that will work since it clearly states that Only standard base-loaded antennas are used Looks like a straight forward scheme to isolate two ports with odd wave-length coax stubs. The paper says only one of the stubs may be extended an extra half wave-length. I suspect the restriction to base loaded coils forces each of the antenna feed points to retain in forced physical hardware something close to their (hopefully) 50 ohm drive impedance at the F-center tuned frequency. That relatively low Z value would hopefully be 1/4 line transformed into a relatively high Z (impedance) value back at the T-Connector. Some type of ensured feed-point decoupling requirement might be involved/required. Comments? Suggestions? Theory? I think we went through that already... men...@... men...@... wrote: The Motorola document is based on the use of the Spectrun base loaded antennas sold by Mother. The Spectrum antenna is a series coil arrangement, not a shunt fed or tapped coil; this is very important! I don't remember seeing any paperwork on the Spectrum Base Loaded Antennas... Out here on the west coast, Mother is a Cookie Company (with decent but hard Oatmeal cookies). I would expect the series coil antenna to be something similar to a 3/4 wave or electrically shortened antenna system and the shunt/tapped coils to be more 1/2 and 5/8 wave. Why would a series coil antenna be a requirement? The chart works quite well for the Spectrum antennas and will probably work for any other series fed LB coil. It will not work for any antenna that is shunt fed as myself and several others found out when trying to make two non-Motorola antennas work on a fire engine. On Low Band with Utility Vehicles, I've found a number of reasons why certain low band antennas don't work well. Depends on each situation and I've recently had an install where only a shunt fed antenna would work. The maker of the Untenna antennas told me once that they could be combined in the same way but the method was different; IIRC the antenna to T cables were to be quarterwaves but were for the opposing frequency. Never tried it and that was a long time ago and no notes to back up my memory. Another document exists that details using a ball mount full length whip and a Spectrum series fed LB base load in the same shared configuration. Milt N3LTQ Quickly looking at a Spectrum Antenna data sheet, I might suspect they are trying to simulate/emulate/achieve a no ground plane halve-wave operation for proper feed-line decoupling. got to go, back later... s.
[Repeater-Builder] Re: Low Band Antenna for both 6 10 meters.
Re: Low Band Antenna for both 6 10 meters. Scott Zimmerman n3...@... wrote: Skipp, How did you work the antenna scheme for this radio? Hi Scott, There are a number of available options. First, I've seen but do not own one of the Comet/Diamond multi-band antennas that does cover both bands plus. I saw one on the back of a guys car at a local flea market and he said it covers multi-bands including both 10 and 6 meters. Don't remember if it was a Comet of Diamond but it was one of those two brands. Another method is to diplex two antennas for each band if you only want to operate within the range of the antennas. There is another trick to cut the antenna long and use a band-width expansion box as previously sold by Antenna Specialists. Probably discontinued by this time... A method to obtain bandwidth at the cost of performance is to use a shortened vertical with a fairly lossy matching network. It's a big time trade and well out of the scope of an easy explanation here on the group. And in a no good deed goes unpunished application I have something similar to an improved Maxcon Antenna Matching unit talking to a number of vertical whips I can swap in and out. An acceptable very wide bandwidth SWR talking to a very lossy antenna matching system antenna is better than no antenna a'tall. Did you use the Motorola docs, or some other method? The Catholic Church says only the rhythm method is allowed. http://en.wikipedia.org/wiki/Calendar-based_contraceptive_methods In my app, I am going to be using a Syntor X on 6 and 10. I was going to use a controller UF output to control a RF relay for the correct antenna based upon what channel the remote base was set for. This leaves room for error both on the part of the controller and idiot doing the programming. (Me) It sure would be nice to have an RF solution (the Motorola cut length cable method) or an internal radio logic way of doing this. You can band detect the RF and coax tr-relay hot switch in the other ranges if you wanted to be that creative. Another option I just thought about is asking a Company like LDG if they make a tuner covering VHF through 6 meters. P.S. I do have a copy of Motorola 68-80100W86 - Diplex Antenna Manual. This document is written for use with standard base-loaded mobile antennas only. Is it scanned into or available in a PDF file format? I'd really like to see a copy if it's available and easily Emailed. Always nice to see how others do things... Scott cheers, s. aka Rubber Chicken... skipp025 wrote: However, you can get a tk-6110 to do both 10 and 6 meters in the same radio. I personally have done the mod a few times, it's not super easy but it can be done.
[Repeater-Builder] Re: Motorola style Rack Clip Nuts
Have a look (obviously the stainless one is on the right): http://www.arcomcontrollers.com/clips.jpg I've not heard this model U, C, Clip Nut ever called a Tinnerman, but McMaster-Carr sells it as a Clip-Nut. As a general rule I believe Tinnerman Nuts are normally one sided. I call it a U-Style Clip-Nut and they are obviously available in many flavors. http://www.mcmaster.com/#clip-on-nuts/=8hn41l It's McMaster-Carr so hold on to your wallet... but they do have everything. And they won't send out a Paper Catalog unless you have a previously verified connection with some higher authority. So use their fairly decent on-line catalog... They also deserve credit for super fast shipping. cheers, s.
[Repeater-Builder] Re: Low Band Antenna for both 6 10 meters.
Re: Low Band Antenna for both 6 10 meters. Get 2 CB whips, Cut 1 for 1/4 wave at 10M and cut the other for 1/4 wave at 6M Build a metal spacer bracket. 3 inches long by 5/8 or 3/4 Drill 2 holes on the end and one in the center for the 3/8-24 hardware. Bolt whips to the ends of the spacer, use star style lock washers. Use a 3/8-24 x 3/4 long bolt and attach spacer and whip assembly to a ball mount. Epoxy a 3 plastic spacer bracket 5 down from the top of the 6m whip to act as a spacer between it and the 10m whip. Don't know if the CB Shops still sell them but we/they used to call them T-Bars. Very popular with the 2 or 3 is better than one crowd. Mount them high enough on the vehicle and you can take-out all the fluorescent lights in your favorite Gas Station with a simple drive-through. Just playing devils advocate here... the above setup is kind of unwieldy for most people and bumper or ball mounts on a newer car is sometimes problematic. You don't really need two different antennas, you can probably fairly easily make or find some type of a dual band antenna with the obvious sacrifice of a bit of band-width. But I'd like to talk on the Amateur Bands and I sometimes need to talk in both the 33 MHz and 43 MHz ranges. One reason I have a few other options in place that clearly trade performance for acceptable SWR. Once again, something small is better than nothing at all... cheers, s.
[Repeater-Builder] Re: the non religious Jesus Nuts
Re: the non religious Jesus Nuts They were also called Jesus nuts by my coworkers, I thought a Jesus Nut was atop a helicopter holding things on or together. If it came off or failed, you normally had an expedited trip to Jesus if you believe in conventional religion. probably named in a spontaneously outburst by some guy who was about to need a tetanus shot. ... if you lost the Jesus Nut on your helicopter, I suspect you will quickly need more than a tetanus shot. So much for drinking a tasty beverage while reading some of these posts...excuse me while I clean up. Ovaltine again? :-) s. ps: can ya tell it's a Friday already?
[Repeater-Builder] Re: Low Band Antenna for both 6 10 meters.
skipp025 wrote: The Catholic Church says only the rhythm method is allowed. I SOMEHOW don't think that 'method' will help us in this situation. Although that's how my third child came along. (3 of 3) A BOY BTW! (Yea, Me!!) Let me guess, you're Catholic, Latino or LDS..? ... or you live on the East Coast where there are a lot of long dark nights, even in the summertime? P.S. I do have a copy of Motorola 68-80100W86 - Diplex Antenna Manual. This document is written for use with standard base-loaded mobile antennas only. Is it scanned into or available in a PDF file format? I'd really like to see a copy if it's available and easily Emailed. Always nice to see how others do things... I thought the above was pretty much common knowledge. Please see the attached PDF file. (Note to Mike Wa6ILQ: Please add to the RB site.) Any chance you or one of the other group members can forward a copy to me direct. Those of us reading the group posts via a web browser don't receive the attachments. I was warned that this document seems to be backwards in that the length of cable that it says is supposed to go to the higher frequency antenna, actually goes to the lower frequency antenna and vice-versa. I'd like to have a look... I would LOVE to know some of the theory behind this method. I was hoping to use this on a remote base antenna with 'Station' type antennas, but I don't think that will work since it clearly states that Only standard base-loaded antennas are used I've got three or four different base loaded coil antennas on the same frequency with a different design. I don't have a clue which one is the Standard Base Loaded Antenna. I know one is reported to be a 5/8 wave antenna, the next a half-wave antenna, another a No Ground Plane antenna and another that's a different un-labeled pile of poop. They all are the similar looking Maxrad models. Comments? Suggestions? Theory? 1. White sauce on Pasta is pretty good. 2. Try the soup and salad on Fridays. 3. You'll eat a smaller dinner if you first have the soup salad. Scott Put Great in front of your name yelled out loud and people in a movie house will often throw toilet paper across the room. (It's OK if you don't get the reference and those of you who do, please seek professional help). I'll have a look at the document and let ya know what might be going on there. s.
[Repeater-Builder] Re: Kenwood TK-690H 29.5-37 MHz, Type 1 radio(s) wanted
James Adkins adkins.ja...@... wrote: Does anyone have or know of someone that would part ways with a Kenwood TK-690H Type 1 low-band commercial rig? Type 1 is the low split, 29.5 to 37 MHz. I would like to purchase 1 or 2 of the units to try on 10-meters. Hi James, Even as a fully Authorized Kenwood Dealer and Service Station I have yet to see the rare low split tk-690h radio. However, you can get a tk-6110 to do both 10 and 6 meters in the same radio. I personally have done the mod a few times, it's not super easy but it can be done. So look for a used tk-6110 radio or in a last act of desperation you can buy a new one from me. :-) I leveled my last one to provide about 45 watts of power from 29.6 to 53.8 MHz in one radio, which I though was pretty impressive. Receiver sensitivity was better than .5 uV across the band. Even if you don't buy a radio from me... I can and would provide you with the information to spread your tk-6110 out. And copies of that information sources were already posted on the web so it's not really rocket science. cheers, skipp skipp025 at yahoo.com
[Repeater-Builder] Re: HYT Repeater vs. Trbo Repeater
Hi Artie, Regardless of what make and model repeater equipment you choose, be sure to actually check the receiver discriminator output performance. I traced problems in a system running LTR and DCS Data back to one model of lower priced desktop repeater receiver. (also known as a two mobiles made into a repeater). The receiver discriminator output was just horrible for any type of data output. I replaced the low cost receiver (the entire repeater actually) with a Kenwood TKR-850 (I sold them) and their LTR/DCS system now works mucho great. CTCSS operation is relatively easy to implement but reliable data requires a faithful receiver discriminator output. Or make sure you have the ability to return the equipment if it doesn't pass the technical muster (requirements) cheers, skipp k2aau k2...@... wrote: Has anyone done any comparison testing between the HYT Repeater and The Motorola Trbo repeater? I am particulary interested in making a future purchase of either one. I have read about the IPsec concerns and that to me is really not an issue. I am sure that HYT will address that concern as time goes forward. From what I have been told, the Trbo consists of 2 mobile radios used for receive and the other for transmit. Whereas, HYT is one radio with a Duplexed receiver and transmitter well isolated from each other. It is also my understanding that the company HYT's vendors are more user friendly in pricing and support compared to Motorola when it comes to accessories, firmware updates and programming. Thanks in advance for any information. Artie k2aau
[Repeater-Builder] Re: unsubscribe (reading yahoo group posts - a butter way - no popcorn)
You guys are silly... Consider changing your group settings to read on the web using a web browser. Then... simply locate the group with your web browser bookmark anytime you want to read the group posts. No flood of inbound Emails for each post or large digest Emails required. Probably drive one to drink (more) if they were subscribed to more than 3 or 4 Groups at one time. Having a yahoo email address automatically signs me into all the groups for which I am subscribed. To read this, the Repeater Builder Group I simply click on the below Bookmark saved in my Web Browser. Once you change your settings to web only (I prefer the traditional or classic view) try the below url and enjoy life again. http://groups.yahoo.com/group/Repeater-Builder/messages If you don't use Yahoo Mail, you might be asked to sign in at the start of your web browsing session, but once you're in, you are in for all the groups for which you subscribe. cheers, s. ps: If you're subscribed to more than one group, here's the page that helps you get your book marks set up. http://groups.yahoo.com/mygroups Now resume normal programming. Your best bet is to setup your email to receive each post in digest form meaning once a day on average you will receive a bunch of postings in just one email into your inbox. When you get around to opening up your inbox you can just scroll through each individual posting, read the ones that interest you and when finished, hit the delete key and they all go away!!! Seeing 15-30 separate, individual emails in my inbox during the course of one day is a bit too much. Try it, you'll like it OM!!73 --- In Repeater-Builder@yahoogroups.com, Jim in Waco WB5OXQ wb5oxq@ wrote: I do not need to read these anymore. I am not mad just getting too many emails.
[Repeater-Builder] RG-223 - RG-142 RG-400 Coax Talk
RG-223 - RG-142 RG-400 Coax Talk Sid purvis...@... wrote: I have seen a lot of jumpers, interconning cables, duplexer cables, etc made using RG-142 and RG-400 (the 400 is preferred). However, RG-223 is also silver, double shielded,very flexible, and also about RG-58 size. Any reason why RG-223 would not work just as well; other than it is not a teflon cable?Sid. RG-223 is quite usable but will have more loss than RG-400 type cables. The question would be if the loss is enough to be an issue. For VHF and Lower frequencies there's not enough loss in short runs to really sweat the difference. At 450 MHz the attenuation/loss in modest to lengthy runs of RG-223 compared to similar size Teflon type coax do start to add up, then it's a judgment call. In longer feed-line runs used at 450 MHz you might want to jump to the next increment/size up coax in the form of 1/2 inch or similar. RG-223 coax seems a lot easier to work with inside very tight spaces where sharp bends curves are required. I believe I have seen it used as the default interconnecting coax used inside a Motorola Radius Style Repeater System (with internal duplexer included). Sometimes you can find real deals on runs of both the Teflon and 223 type cables. s.
[Repeater-Builder] Re: Dielectric diplexer
bil.isom bil.i...@... wrote: I have just been told I am about to receive a dielectric brand diplexer rated at 25000 watts on 191 Mhz from a analog TV station. I feel a little bit like the dog that catches the car he is chasing. Now that I have it, what can I do with it? Any ideas? Can it go to 220? Does anyone have any experience with these? Thanks Bill N4XIR I'm thinking duplexer and/or cavities for any of the VHF and some UHF Bands if you do the proper homework. s.
[Repeater-Builder] Re: DOSBox to Program Radios
Aristotle Zoulas jrzou...@... wrote: Well, I go by the Repeater Builder Web site that states not to use emulators and various other methods to imitate a slow computer. Exact Quote below: Why slow the computer down? I picked up a fully working Compaq Laptop on ebay for $20, works great for dos programs. A low end computer running MS-DOS (486 DX50 - i.e. maximum clock speed of 50MHz, with all cache memory disabled), and using a faster computer WILL turn good radios into bricks). Don't even think of running ANY version of Windows - this has to be a straight DOS computer. We are NOT kidding here. This is one case where slower is better, and going to a 486-33 or even a 386 wouldn't hurt. The required characteristics of the programming computer are described in depth on the RSS pages mentioned above. I'll have to make a note to go back an unprogram the Syntors I just hit with a 2.8 Panasonic Laptop. Everything has to be taken into context of course. I keep a dos computer in the service vehicle but rarely pull it out anymore. I boot to a thumb drive running dos 5 and program any radio I need to hit without slowing the smoking fast computer down one bit. Some tricky radio programming software requires cache disabling but I can do that with a free utility and get on with the show. Tastes Great, Less Filling... The newest revision of the Saber software is still too old to have the speed fix that is mentioned there applied. I repeat, find an old DOS computer no faster than 50mhz and with a real COM (serial) port. Desktop or laptop, it doesn't matter, except that many laptops do not give you the option to switch off the cache memory. While I'll admit I haven't had to reprogram a Saber in well over a year or more... I consider the rest cannon fodder. You don't need the computer to offer you the cache off option, it can be forced off with a simple utility and there are a number of freebies on the web available for download. Off to never, never land. s.
[Repeater-Builder] Re: TKR-750 Crunchy/Grungy Weak Signal Audio
Bob - AF6D b...@... wrote: Why the grungy audio? Primary Suspects: 1. LMR Feed-line (gotta go) 2. Duplexer Alignment (verify with the proper test gear) 3. Repeater Pre-selector Alignment. How did the Dealer align the receiver front end? Most people use the peak for max signal method and that's not the best. I reliably work our local 2500ft repeater sites from 25 plus miles distance with a 200mW power setting on an HT inside the vehicle. If the signal is not reliable, I go looking for the reason(s) it is not. s. [the story] My 2 meter TKR has worked fine for about a year but has always had a problem on our frequent weak signals. We're a mountain community and CERT/RACES/ARES/Skywarn users are often on HT's. There are a couple of towers in the neighborhood at 6,400 feet over southern California (it's kewl living at a repeater site) and on my own gear I don't hear anything on a weak signal beyond the norm. But on the TKR it just sounds dirty. Grungy. Crunchy. There are commercial sites within one mile with high power paging but we've detected no intermod. We did have a bout were grungy audio was breaking PL and hanging until timeout. But that went away. The Wacom 6 cavity WP-642 is tuned dead on and offers excellent isolation and rejection (at a cost of 2-3dB loss on TX sigh). Another TKR user at a high elevation commercial site reports similar experiences. Yet another TKR owner reported that his is excellent and yes the audio is good. Just not for us on weak signals. He suggested perhaps an RFI issue but from where? Our installation is modest and constrained only by my lack of time and funds. My daughter is sick and I live in a hospital with her, so be gentle HI HI. The very large guard dog watches the house. The antenna is a Hustler G5-144 tuned with a MFJ 259, dead on and above the repeater through an insulated roof by about 30 feet. We have no desense. It is fed with LMR-400 just because I haven't put hard line on it. No preamps are installed. At 6,400 feet not much is needed. The receiver is .18uV. The TKR hears very well compared to my FT-847 with an antenna 20 feet lower. Why the grungy audio?
[Repeater-Builder] Re: TKR-750 Crunchy/Grungy Weak Signal Audio
Repeater Pre-selector Alignment. How did the Dealer align the receiver front end? Most people use the peak for max signal method and that's not the best. We used the SINAD method There's a sample port in the receiver front-end for use with a tracking spectrum analyzer. The results of the Sinad Method are sometimes less than optimal. s.
OT Re: [Repeater-Builder] DOSBox to Program Radios
If your computer will boot to a Thumb Drive, configure the thumb drive to boot dos and run from the external drive when you want to program legacy radios. I don't even bother to slow my fast laptop down when programming old radios (Syntors, etc). But some software only works well when you disable the processor internal cache, which I do with a simple (free) utility. So the same latest and greatest laptop can do both XP ( newer) and boot/run the old stuff. s. La Rue Communications laruec...@... wrote: Finally - another Mac fan surfaces! :-) I have tried using DOSBox on our WinXP, however have had ZERO luck on the serial port recognition. Fromw hat I heard, the emulator will not recognize serial ports. Is that why you have resorted to the USB dongle? I cant remember if DOS ever recognized USB accessories. THats news to me! THanks for the tip! John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn - Original Message - From: Tim - WD6AWP To: Repeater-Builder@yahoogroups.com Sent: Monday, August 09, 2010 7:02 AM Subject: [Repeater-Builder] DOSBox to Program Radios DOSBox (www.dosbox.com) is an x86 emulator with DOS. It works great for programming those radios that need old, slow PCs for the software. I use it on my MacBook dual booting into Windows 7 and using an IO Gear USB serial dongle on COM1. So far I've programmed a couple of Radius M1225's and a VXR-5000. A friend of mine has similar results with Windows XP on a 800Mhz PC with a real serial port. -- Tim
[Repeater-Builder] Re: Dissasembly of msr 2000 continuous duty amp. How?
Bill jawjabill...@... wrote: Apparently no one here got the moto memo on working with giant heat-sinks. I never did during my tenure... memo's usually floated in well after the fact or damage done... First you only need a 30-40 watt iron to work on them as moto did at the factory The secret is .. raising the heat-sink to about 3-400 degrees while you are working on what needs to be done. We Moto types in the field... never had the luxury of all the factory recommended service tools. Half the time I was happy the heater or AC actually worked... : PS .. don't touch it with fingers or arms. This technique also lowers possibility of cracking the ceramics. I usually lay out everything that has to be done in advance with extra planning. Hey, I didn't say it was going to be quick... Bill Atlanta The best way to pre-heat up any PA heat-sink is to place it in Taxi Cab Full Duplex Base-Station service in any large city. Those of you who have experienced the application know exactly what I mean. Yeah, watch your fingers... cheers, s.
[Repeater-Builder] Re: Dissasembly of msr 2000 continuous duty amp. How?
Tom Parker t...@... wrote: Why has no one suggested replacing the guts of this beast with a Mitrek PA? Only if the Mitrek VHF PA is the same animal as some Micor PA's are reported to be. ... and that you can a used Mitrek (with the matching parts) as easily as you can find a used Micor parts radio. Or the converse... s.
[Repeater-Builder] Re: Measuring duplexer insertion loss
Can somebody please explain how the insertion loss of a Duplexer is properly measured using a HP 8920A (with Spectrum-Analyzer). Jeff DePolo j...@... wrote: 1. Connect duplexer Tx port to duplex port on 8920. 2. Connect antenna port on duplexer to antenna port on 8920. I have to think if where you apply the source and sample matters in this example and why. One should be able to apply the Duplex Output Source Signal to the antenna port and sample each outer leg (back to the antenna port). The unconnected leg/port should probably have a termination (load) on it. Might matter more or less maybe depending on where the other half of the Duplexer is tuned. Hm...? For example, if you're generating 0 dBm, and the amplitude at the marker is -2.10 dBm, and you have 0.5 dB of patch cable loss, the insertion loss through that leg of the duplexer is 1.6 dB. Another relative comparison is to insert a barrel connector in lieu of the duplexer to get a relative idea of the cable loss (with the barrel in line). s.
[Repeater-Builder] Re: Desoldering MSR-2000 Rcvr and PA PC Boards
Eric Grabowski ejgrabow...@... wrote: I'm not sure about the MSR2000 ... Motorola uses multi-layer PC boards in most of their radios. Yep, they do in the newer ones, especially the portables. I've had experience with 4 and 6 layer boards but this one looks to be just a plain vanilla 2 layer board. The VHF MSR-2000 CD PA PC Board is a 2 layer board. Wattage is of less importance than tip temperature and size. I tend to agree but for soldering/desoldering components to/from large groundplanes wattage does come into play. Well... not really. You need enough wattage to heat the right size tip. A large tip 35/40 watt iron can be kind of a popcorn fart. Like formatting an old MFM Hard Drive, you'd better have some serious extra wait time available. Personally, I've found that I get better results using a little hotter iron for a shorter period of time. The joints look better and the components stay cooler than if I had used a cooler iron for a longer time. Depends on technique... but fast and hot (enough) on/off soldering ( removal) should work pretty well. Others have good luck with the grill and kill sometimes excessive time-on the PC Board soldering technique. YMMV. I think I may have first heard about this technique from building Heathkits back in the day. Also, I believe Skipp mentioned this technique in one of his responses (maybe not on this particular thread though). This is the only thread I've replied to... :-) Skipp wrote: Yes (Motorola used a higher temperature solder on the MSR2000 units) Well, ok then. Since I've got a few more MSR2000 receiver and exciter boards to fix, I guess I'll start hunting for a tool more suitable for the job, i.e., one with a higher temperature and more mass. Thanks to all who responded. 73 and aloha, Eric KH6CQ Cheers Eric, I can use the same large vintage iron for different types of solder and temps if contamination (purity) of the solder is not an issue. It doesn't have to be excessive in size, just enough, for the city. s.
[Repeater-Builder] Re: Desoldering MSR2000 RX PCB
Thomas Oliver tsoli...@... wrote: For de-soldering I use a de-solder iron with a squeeze bulb on it from Radio Shack, works great. http://www.radioshack.com/product/index.jsp?productId=2062731 tom Nice for most things but not removing the final modules from an MSR-2000 and/or Micor RF Power Amplifier. You'd need a lot more mass. s.
[Repeater-Builder] Re: Desoldering MSR2000 RX PCB
Eric Grabowski ejgrabow...@... wrote: A recent thread discussed a problem disassembling a MSR2000 continuous duty PA. That triggers this query: Does anyone know if Motorola used a higher temperature solder on the MSR2000 units? Yes s.
[Repeater-Builder] Re: De-Soldering Motorola MSR-2000 Micor RF PA Substrates
Eric Grabowski ejgrabowski@ wrote: A recent thread discussed a problem disassembling a MSR2000 continuous duty PA. That triggers this query: Does anyone know if Motorola used a higher temperature solder on the MSR2000 units? skipp025 skipp025@ wrote: Yes s. wb6dgn wb6...@... wrote: What do they use? What alloy? Seems that radio was out too early for RoHS? Tom DGN Don't know what specific type of solder Motorola used in the MSR-2000 PA Sections but I do know the type was changed or updated at least once. The early A version PA's had serious teething problems (meaning most failed unexpectedly early) and just plain died without notice (within the Warranty Period). The B version MSR-PA was offered up as a retro-fit trade in fix warranty replacement to resolve some of the A Version mortally terminal design issues. I suspect Part of the MSR-2000 B-Version PA rework probably included revising the solder type. I don't know what they used but I have three or four different types of solder in use depending on the requirement. High RF Current points within a working RF solid state Amplifier can often get very hot. It's not uncommon to have certain areas become so hot, the parts start to unsolder themselves. I've seen more than a modest number of RF Amplifiers with self un-soldered parts in/at the typical high RF Current locations. A classic retrofit fix is to remove and re-flow High RF Current Connections with a higher quality, higher melting point Solder. In more than a few examples the solder upgrade doesn't really solve the problem and a re-design is required. The Engineer is now tasked with really understanding the requirements of High RF Currents and unwanted localized heating within the MSR-2000 Micor or any similar RF Amplifier circuit design. A number of the External 100 watt and above - level RF Amplifier mfgrs suffered very similar or same issues. They didn't have a realistic estimate for the cost of lunch. s.
[Repeater-Builder] Re: Dissasembly of msr 2000 continuous duty amp. How?
The amplifier in question is a MSR2000 VHF, not UHF - no ceramics to worry about - no oven required. Kevin Don't know what you'd really use the Oven for... For the VHF PA (like the Micor) I switch from the mondo iron to the trusty Weller 550 and 8200 guns. I feel it's better get on and off a section as quick as possible. Weller also makes a decent size iron like the WP-60. s.
[Repeater-Builder] Re: Dissasembly of msr 2000 continuous duty amp. How?
martinfriedman67 radi...@... wrote: Our Amateur radio club's Motorola MSR 2000 continuous duty amp needs repair. I cant figure out how to remove the amp board from the heat sink. I removed all screws from corners as well as the transistors. It seems to be held by the center, just below the tall air variable cap. I tried heating the solder in the area but, no joy. I don't want to crack the board. The drawings in the manual I found here do not show even the screw holes. Thanks in advance, 73, Marty (WB2BEW) Been there, done that, coffee mug and T-shirt It's not easy... I'm doing two MSR-2000 PA's right now (just in the door yesterday) and I completed my last MSR UHF PA repair a year or two back. Everyone has a different technique and mine depends on the specific failed stage/parts. I use a very large mass soldering iron (better than a gun) to quickly get on and off the portions I need to deal with. I reflow the solder in most of the anchor places using a small amount of new (solder) and lots of quick on/off, well spaced long-time to slowly cool down... between applying the iron to repeat locations. Then comes a decent amount of quick on/off Solder Wick to remove much of the original and added solder, then flat blade X-acto knives (and razors) to carefully wedge up the securing contact surfaces. Sometimes I can and do reflow a bit of solder back into the cleaned section during the flat blade lift process as a method of quickly transferring heat to a very localized area/spot. The key is to get/keep the ceramic substrate as cool as possible. The MSR Power Supply pins poke up into the substrate(s) ... The entire project including obtaining the parts from recycled radios takes me about 4.5 hours with beverage of choice and some decent AM Talk-Radio playing at low back-ground volume level (no, not the right-wing whack job stuff). Once you've had to do this type of Motorola PA repair, you more fully appreciate trying to keep the amplifier happy and cool. cheers, skipp
[Repeater-Builder] Re: Dissasembly of msr 2000 continuous duty amp. How?
radi...@... wrote: OK Kevin, I had already tried the desoldering with a really good Pace unit, but the heat did not transfer well. Yep, not enough heat available from most solder suckers, irons and guns. I will get a buddy to help and use my Weller guns. I have a big 250 watt one here somewhere. Marty The Weller 550D gun is probably the smallest gun you can realistically get away with using. I use the mass of an old martial-aid size soldering iron, which are often passed over by uninformed souls shopping at Ham Flea Markets. s.
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
Re: Simrex - GLB Pre-Selector Verus You're actually comparing two different boxes. no6b@ wrote: Nope - comparing GLB vs. GaAsFET/pass cavity combo Still not the equivalent box... you're still missing the post active-device stages. I don't need them. But I suppose one could add a 2nd pass cavity AFTER the preamp. I've never had to do that in ~30 years of repeater building. I have used post preamplifier filters in the interest of managing extremely high signal levels. Care to publish your results here? Why don't you tell us what you found? I've asked more than once for some reason you're reluctant to publish your results. I can't help but be even more suspicious of the GLB. Because of time... I can post things only when I have the available time and quickly replying in detail requires that I should probably review my notes. If those notes are not readily at hand you will obviously just have to wait. Lacking the hard data, I'm going to do a little guesswork here: a typical GaAsFET preamp has 17 dB of gain @ 440 MHz. The GLB Preamplifier I repaired has a dual gate Mosfet. The version I received had a blown device so I replaced it. With different amounts of bias I could actually get up to nearly 25dB. The NF of the device alone depending on the bias was anywhere from about .7 to 1.2 dB again depending on the bias. The Simrex preselector has a spec'd overall gain of 8 dB. Which is similar to what I ended up with after replacing the bad Mosfet and selecting a bias point resulting in a gain of about 9.2dB through the box. All other things being equal, the combined loss of the resonators in the preselector would then be 9 dB. Kevin says the distribution is 2 stages before 2 after. The 224 MHz version I have here is 1 before and 3 trailing stages. If all the stages are equivalent, then the pre-active device loss is 4.5 dB. Assume 0.5 dB NF of the actual GaAsFET device, I come up with 5 dB NF. Am I close? Using your above figures with one pre-device stage... figure about 2.3dB and .7 for 3dB NF at 224 MHz. Yeah, but the numbers are off. To properly compare the two you'd need to use more than one pass-cavity. At least one additional cavity (min) following the active device and to really be honest, more than one trailing BP Cavity. See above, Kevin's post. In many cases, the trailing cavity isn't needed. But not in every case... If you're trying to manage extremely high signal levels the trailing filters can greatly help filter unwanted RF. A single pass cavity usually has enough out-of-band rejection to be totally adequate on its own - no post-preamp filtering needed. The post-preamp filtering can and does contribute in the management (not necessarily the prevention) of high signal levels issues. ..only for RXs that need it. I guess I'm a bit biased because I use real RXs (GEs), so the only protection needed is for the preamp going in front of it. Depends a lot on the specific situation... the last real GE receiver front end I swept had a modestly wide front- end. Although it might have survived only better than some other brand and model receivers there are situations where post preamplifier filtering before the receiver would be a real benefit. Then again, the fact that post-device filtering is used in the GLB makes me worry about the actual selectivity ahead of that device. If there's only 1 or 2 resonators ahead of it, that's not much protection. A 1/4 wave bottle will provide much more rejection ahead of that first amp, and with less loss hence lower NF. There are 2 resonators in front of the Active Device. The higher Q of a 1/4 wave cavity is obviously better. The honest to thyself person should determine the NF difference, which is probably not a huge amount. Once again, I'm still waiting for the NF numbers. See the above... IMO the Simrex amplified preselector is a space-saving compromise, nothing more. Bob NO6B Sure, it's a compromise that works well for what they are. I'd probably (and do) park a Simrex or GLB Pre-selectors in front of less than bullet-proof receivers. Something else to consider: if your less than bullet-proof RX has good sensitivity, a preamp isn't even needed - just throw a pass cavity in front of it. Simple cheap, you'll probably still end up with better sensitivity than if you used the Simrex preselector. Bob NO6B Because a number of less than bullet proof receivers don't have great sensitivity. And the response (shape) of a pass cavity is different than a multi-stage pre-selector. s.
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
The better skirts are mucho desired. n...@... wrote: As you so often like to state, it all depends on the application - in many cases it simply isn't necessary. And in many cases it's beneficial to have better skirts... But there are other solutions: if you want a brute-force window filter they're out there too. I have a few 5 MHz wide 1 dB loss UHF filters sitting on the shelf here that I acquired at the Dayton Ft. Tuthill hamfests. ~$40 each. Seems like a good deal... but the 5MHz band-width is only (for me) usable in some system applications. Some of those applications where the 5MHz band-width would be excessive but the expected Simrex band-width would not be... Again, the loss is low enough that in most cases a leading preamp simply isn't needed. Leading or Post Preamp? Kind of makes it look like helicals are a sin doesn't it... Ever wonder why the MVP/MastrII Micors are so deaf compared to more modern RXs? Nope... I haven't measured the loss of the UHF helical assembly, but the VHFHB front-end helicals have ~6 dB of loss. In all those radios, their own helicals effectively are all the post-preamp filtering you'll ever need. No it isn't... if you sweep the front end of Micor you'll find it's actually fairly wide. I seem to remember sweeping some GE Receivers and their front ends were relatively wide on the order of at least a few MHz. From Memory I seem to remember the Micor being at least 4MHz wide. The GLB preselector preamp has 4 helical stages of unknown (unknown to me) coupling. Depends on the Pre-selector Model and age of the box ... I have GLB units here with two pre-device stages and three post-device stages. And I have versions with a more traditional helical design and others with more of a lumped parts layout. A 2-Meter version I have lots of pictures of has 1 stage of pre-selection and four trailing stages. The active device is an MRF-901. OK. MRF-901 NF @ 2M is ~1 dB, so maybe 2-3 dB NF for the unit. And that jives with my informal recorded notes for the 224 MHz GLB Pre-selector with a dual gate Mosfet. Not bad for VHFHB, but having only 1 little resonator in front of the active device doesn't offer it much OOB protection. Better put a (gasp) PASS CAVITY in front of it! ;) To quote someone who recently wrote: As you so often like to state, it all depends on the application - in many cases it simply isn't necessary. However, In more than a few real world situations you might really need the filter pre-selection a lot more than the most optimum NF. A practical trade of pre-selection for a slightly higher noise figure can and does sometimes make the difference in a usable radio system. OK fine. But again, we DON'T KNOW the noise figure for the device. It's not mandatory to know the NF for every situation, only helpful for those specific situations where making a logical assumption is not allowed. Furthermore, since the filtering distribution varies with the model, it's very difficult to predict the dynamic range characteristics of the unit. True along with the different active devices. Fun to play with? Yes. Can solve some IMD/overload problems? Certainly. But not a tool for any seriously engineered RF system. Bob NO6B Really depends a lot on whose money you're spending. I've seen a lot of seriously engineered RF systems that don't work very well out there in the real world. s.
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
Re: Simrex - GLB Pre-Selector Pre-Amplifier n...@... wrote: Then we're back to the pass cavity solution. Just saying there are other inexpensive, well-engineered options out there. Sure, the pass cavity is one of many possible options. The VHF HB MVP front-end helical assembly has a 3 dB BW of 1.8 MHz. At 40 dB down the BW is 5.7 MHz. Granted the selectivity curves of the Simrex pre-selector curves are narrower, but keep in mind that they are in fact misleading, since most of that selectivity is AFTER the preamp stage. My question to you is... what function would you think the multiple section/stage post active device selectivity serves? Add to that the fact that the mixer in the GE radios has very high dynamic range (remember, the stock GEs don't have a gain stage ahead of the mixer), you likely end up INCREASING the GE's susceptibility to IMD by using one. Depends on what you park in front of the receiver. in the above example the Simrex preselector isn't necessary: simply omit it use just a pass cavity. Once again a pass cavity is totally different compared to the Simrex GLB Preselector tuned circuits. To equate the two layouts you would need to add trailing resonant filters, which are in many examples tighter/sharper than the front end selectivity of the following receiver. If I tried to provide some type of speculative explanation regarding the Simrex GLB Preselector Management and/or control of extremely high level inputs, IMD and unwanted signals through the trailing helicals... you'll probably jump on the not a well-engineered label again. So I'm not even going to try and I'm pretty much outta this subject thread after this reply post. It's not mandatory to know the NF for every situation, only helpful for those specific situations where making a logical assumption is not allowed. Kind of like saying you don't need to know how much output power your TX is running, so long as your users can hear it. Sure... kind of If I assume the Tx Power of a 100 watt Power Amplifier is within 15% of its nominal rated value based on indicated current draw, supply voltage, a spectral view and knowing the output path to the antenna is working properly... I should be able to make a logical assumption users within a normal expected coverage area should be able to hear the machine... even though I've never measured the output with an accurate watt meter. Fun to play with? Yes. Can solve some IMD/overload problems? Certainly. But not a tool for any seriously engineered RF system. Bob NO6B Really depends a lot on whose money you're spending. I've seen a lot of seriously engineered RF systems that don't work very well out there in the real world. ... and in almost every case I've seen this, it's due to the engineering failing to take into account all of the real-world parameters. If your models are flawed, everything falls apart. Bob NO6B In the most (unfortunately to many) recent examples of poorly preforming RF Systems I've seen up close were due to the lack of the Engineers, interest, experience knowledge not including the mention of the bureaucracy or incompetence placing that person on the project. s. That's it for me... cheers
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
Re: Simrex - GLB Pre-Selector Pre-Amplifier Jack Chomley ra...@... wrote: Well, I have decided to buy and try a Simrex Pre-Selector,experiment with it, test it ...whatever. Something to never say in an airport... Hi Jack, Hopefully you will find the Simrex / GLB Pre-selector to be a very interesting and useful box. There are multiple stages of filtering in front and behind the active device. During the earlier posts I tried to highlight the difference between the additional filtering although I didn't (want to) go into much detail about at least one under-played advantage of having post filtering stages after the active device. If we were to actually compare the pre-filtering against a high Q band pass cavity, you will see a different shape band pass due to a single cavity versus a multi-stage layout. You could and most likely would see a lower loss similar shape if you had two or more series high-Q band cavities in front of an external RF-Amplifier (not even addressing the post filtering). A real world question ... is the size, cost and hardware complexity of the High-Q Cavities with a separate RF Pre-Amplifier configured in the same layout as a Simrex / GLB circuit going to yield a major advantage in your specific application? Will the Simrex / GLB Pre-selector provide a benefit to your system? In many of my personal experience examples using a GLB Pre-selector has clearly improved the receiving system performance. At the very least I will learn something from my experiences and it may end up being useful to me, anyway. It's nice to read that you're willing to make the effort and spend money for the education. I expect you won't be disappointed with your Simrex unit. I certainly appreciate the different points of view here and have learned of alternative methods and the reasoning behind them. The jackpot of knowledge... and you weren't even in a Casino. For me, all of it is good information :-) 73, Jack. VK4JRC Cheers Jack, s. Sent from my Apple iPad Tablet PC Response sent from a painfully slow dial-up internet connection.
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
Re: Simrex - GLB Pre-Selector Verus You're actually comparing two different boxes. n...@... wrote: Nope - comparing GLB vs. GaAsFET/pass cavity combo Still not the equivalent box... you're still missing the post active-device stages. I have measured all the original GLB Pre-selectors and their performance values are very realistic (no surprises). Care to publish your results here? Never thought about it much... those who were honestly interested in the subject the last time we rehashed the GLB active device topic here on the RB Group Emailed me direct and we exchanged various notes, diagrams and information. Much of what I have is based on the Pre-selector with the dual-gate mosfet, which I believe is similar to the BF-998 device. GaAsFET preamp is ~$130. I don't think I've ever paid more than $50 for a pass cavity, so the total is ~$100 less than the GLB unit. Reads like you're comparing a new Preamp with a used cavity against the price of a new Simrex (GLB) Pre-selector. That's not really fair... Perfectly fair. Used pass cavities in good condition are plentiful. Can't remember the last time I saw a used GLB or equivalent unit for sale, so I'm simply comparing what's readily available. Yeah, but the numbers are off. To properly compare the two you'd need to use more than one pass-cavity. At least one additional cavity (min) following the active device and to really be honest, more than one trailing BP Cavity. A single pass cavity usually has enough out-of-band rejection to be totally adequate on its own - no post-preamp filtering needed. The post-preamp filtering can and does contribute in the management (not necessarily the prevention) of high signal levels issues. I don't really care to detail out the above text theory but I will say I feel it's a critical often over-looked (at least in this RB Group - threads example) subject. Then again, the fact that post-device filtering is used in the GLB makes me worry about the actual selectivity ahead of that device. If there's only 1 or 2 resonators ahead of it, that's not much protection. A 1/4 wave bottle will provide much more rejection ahead of that first amp, and with less loss hence lower NF. There are 2 resonators in front of the Active Device. The higher Q of a 1/4 wave cavity is obviously better. The honest to thyself person should determine the NF difference, which is probably not a huge amount. IMO the Simrex amplified preselector is a space-saving compromise, nothing more. Bob NO6B Sure, it's a compromise that works well for what they are. I'd probably (and do) park a Simrex or GLB Pre-selectors in front of less than bullet-proof receivers. If the active device in your Simrex / GLB Pre-selector is a decent GasFet layout, the only major difference is the pre and post resonant circuits and how helpful/useful they are (or are not) in your application. s.
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
Re: Simrex - GLB Pre-Selector Pre-Amplifier Kevin Custer kug...@... wrote: While the skirts and OBR of the GLB might beat a single cavity, many times it isn't necessary - The better skirts are mucho desired. especially if the receiver that follows is able to cope with high out of band signals and the preamp that follows the cavity has a high overload point. The question in each example/application is how well and is it enough... The problem is, like any receiver that has several helicals in cascade before the first active stage, the loss that precedes the active stage has a majority role in the overall NF of the system that follows. It matters little what the quality of the active stage is, because the loss has already determined (for the most part) the system Noise Figure. Kind of makes it look like helicals are a sin doesn't it... The GLB preselector preamp has 4 helical stages of unknown (unknown to me) coupling. Depends on the Pre-selector Model and age of the box ... I have GLB units here with two pre-device stages and three post-device stages. And I have versions with a more traditional helical design and others with more of a lumped parts layout. A 2-Meter version I have lots of pictures of has 1 stage of pre-selection and four trailing stages. The active device is an MRF-901. And the coupling for this model is a slightly different method than some (not all) of the other models I have looked at. Kind of interesting how the various models differ... I do have a number internal view pictures of GLB Models if anyone really burns to see them. If they are over-coupled (and I believe they are not looking at the response curves) only a few dB of loss will occur before the active stage. If they are lightly coupled (which I believe is true) then several dB of loss occurs ahead of the active stage. Both the above situations occur depending on the band/model and production version. The coupling of the one model I have nearby is with/a (relatively) high-Q capacitor probe. Another vhf model uses a more traditional wire probe layout. Every dB of loss ahead of the first active stage ADDS to the system NF - period. This loss can NEVER be recovered no matter how good the preamp is that follows. Kevin Yep. However, In more than a few real world situations you might really need the filter pre-selection a lot more than the most optimum NF. A practical trade of pre-selection for a slightly higher noise figure can and does sometimes make the difference in a usable radio system. The lunch my not be free, but it doesn't have to cost a lot. now go do the right thing cheers, s.
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
Re: Simrex - GLB Pre-Selector Pre-Amplifier Yes, but the NF is unpublished unknown. I therefore assume it's poor, maybe 3 dB? Once again, the NF depends on what device arrives in your specific Simrex (aka GLB) Pre-Selector. It wouldn't hurt or be impossible to ask. A Chip Angle GaAsFET @ UHF has 0.5 dB NF. Put a 1/4 wave pass cavity with 0.5 dB loops in front of it you have a narrow 1 dB NF front-end. I'll take 1 dB NF over 3 dB NF any day. You're actually comparing two different boxes. The Angle, ARR, Telewave, Hamtronics, yadda-yadda brand Pre-amplifiers are just Pre-amplifiers. The Simrex / GLB box is an RF Amplifier with both Pre and Post filters. The lower realized gain of the Simrex / GLB unit is directly related to the additional filtering included inside the box. The Simrex unit makes a nice solution if you don't have the physical space for a 1/4 wave bottle. But it's not the primary reason why I like them. Then again, I know someone who just ordered an even smaller MtronPTI front-end crystal filter to solve a front-end overload problem from a TX over 1 MHz away from his RX. Crystal filters can be very helpful but people tend to depend on them to cure a Symptom. Not the best solution (higher loss, can't be re-tuned if he ever has to change freq.), but I guess it works for him. Sometimes you need a large brick wall with only a small doorway so they obviously have their usefulness. If you picked the UHF Simrex unit with less gain, more selectivity than the standard model, then the noise factor should be better? The less gain is related to the internal filtering stages, not the device. I would expect the version with the GasFet to have the typical expected NF for that device. Any other available active devices to have Noise Figures commensurate with their typical expected values (for those devices). I doubt it. But without any real NF numbers, it's all guesswork. I have measured all the original GLB Pre-selectors and their performance values are very realistic (no surprises). I wouldn't expect a surprise/difference if I ordered the GasFet equipped Simrex Pre-selector. I guess it comes back to price too, a 1/4 wave can plus pre-amp will cost more money... No, your selection should be based on your needs. Do you need a bare RF-Pre-amplifier or do you need an integrated, amplified RF Pre-selector box? GaAsFET preamp is ~$130. I don't think I've ever paid more than $50 for a pass cavity, so the total is ~$100 less than the GLB unit. Reads like you're comparing a new Preamp with a used cavity against the price of a new Simrex (GLB) Pre-selector. That's not really fair... One of the really nice (and mostly overlooked) items about the Simrex (GLB) unit construction (and operation) is the Post (active) Amplifier Filtering (tuned circuits). For more than one real reason they can be one of the most under reported bacon saver in your fry pan. s.
[Repeater-Builder] Re: TKR-750 RF Preamplifiers
Re: TKR-750 RF Preamplifiers Com/Rad Inc com-...@... wrote: Have any of you experimented with a RX pre-amp for the Kenwood TKR-750 repeater? Yeah, once or twice... I am seeking results of actual trials of a product - 'bout killed myself once trying a Thighmaster... Anyone care to comment on their experience(s) ? Hurt a lot in the groin area and took a while to heal. Thanks in advance Ed Folta Where and what you do with a preamp should depend on the location, application and duplexer (antenna system). In most casual situations (not a a major comm site with other adjacent repeaters and a broadcast station or two nearby) pretty much any type of decent preamplifier works very well. I like the ARR Preamplifiers because they work well and are often found fairly cheap on Ebay. The old GLB (now owned by someone else) are very good layouts for busy locations. Other people have told you about Angle Linear and I'll throw in both Telewave and Hamtronics as a source. Everyone wants to dance and sing about GasFet and Phempt device preamplifiers but there is more than a valid case around to obtain and use bipolar device versions (preamps) ... And you'll hear lots of opinions about how much gain to use/buy. Depending on whose camp you're in the reply might be that x-amount is enough to not much all the way to the other extreme where as much as you can. And the amount of gain you end up with should again depend on you specific situation. I tend to lean toward the as much as you can side because I like to use mostly hand held on low power portable radios. I can work my 22 mile distant ham repeater from inside my house with less than 1/4 watt of power. So the real answer to your question might be... where ya gonna put the repeater? s.
[Repeater-Builder] Re: Simrex - GLB Pre-Selector Pre-Amplifier
Re: Simrex - GLB Pre-Selector Pre-Amplifier The Simrex (aka GLB) units are actually amplified pre-selector assemblies, not just plain wide-band Receive Pre-Amplifiers. There's a reason why these units offer/spec 8dB Gain versus the others un-protected preamps. The less obvious gain when compared to traditional GasFet and BiPolar RF Preamplifiers is due to the internal integrated pre and post filtering. What does it all mean... If you have some types of IMD grunge problems when trying a regular GasFet/BiPolar Preamplifier, chances are your results using the Simrex/GLB pre-selector might be better. The pre and post filtering inside the Pre-Selector is a big deal. s. Jack Chomley ra...@... wrote: This unit looks like the answer for me..I think! I am in the process of building 2 repeaters on 70cm for possible emergency use by our Amateur Radio Club. Both will be very portable, I have Vertex VX-2200 radios for one, Hamtronics T304/R306 boards for the other. In keeping the units very portable, I am using these filters http://www.polarelectronicindustries.com/model.php/model_id/983/ These filters are being used due to portability, but I have reservations about performance IF my systems end up sited close to other equipment. Would the Simrex unit offer advantages when used with my filters? I would look to getting the higher selectivity spec, in preference to gain. 73, Jack. VK4JRC Sent from my Apple iPad Tablet PC On Jul 30, 2010, at 6:20 AM, Steven M Hodell st...@... wrote: More great info from Frank @ SIMREX. Steve ~ KA1RCI - Original Message - From: Frank Neuperger To: fr...@... Cc: Steven M Hodell ; maqui Mike Aquilino ; sa...@... Sent: Thursday, July 29, 2010 4:15 PM Subject: Re: [Repeater-Builder] Fw: TKR750 -Preamp Steve, That did not post to the list because I don't have membership. I would appreciate if you would forward to the list on my behalf. Regards Frank On 7/29/2010 3:58 PM, Frank Neuperger wrote: Steven, Thanks for the vote of confidence. We sell them to Hams (Ham frequencies) for $275($25 less than 2-way dealers) as a gesture to Gil Boelke (silenet key) who developed the preselector and founded GLB (now owned by SIMREX). Note that the standalone preselector is still made in house by staff that were trained by Gil and on tooling built by Gil. It is also the front end of every SNRDS-II radio. Same radios that are part of many FAA and other Federal systems. Standard gain is 8 db For +$25, you can order it with ~4 dB gain and steeper skirts on the filter or ~11 dB gain and gentler slope on the filter skirts. For extreeme interference, one usage of the preselector has been to place a coax stub notch filter between the antenna and the preselector. I have done ~3MHz spacing of the notches of the comb for a marine radio BASE application using ~ 35?? feet of LMR 400 for my stub. One of the notches was placed directly onto the frequency of collocated marine base station giving us an extra 22dB of suppression at that frequency. Using excessive length of coax resulting in a comb allows the overallbandwidth to repeak steeply and with minimal loss between the notches of the comb. A single notch approach (not a comb) when placed close to your desired carrier will often have unacceptable insertional loss at your desired frequency.The comb notch filter is just extra coax and minimizes the insertion loss close to the notch. . The calcs for length are not too difficult. Warmest Regards Frank Neuperger Simrex Corporation VE3FNZ - Original Message - From: Steven M Hodell To: Repeater-Builder@yahoogroups.com Cc: sa...@... Sent: Thursday, July 29, 2010 2:34 PM Subject: Re: [Repeater-Builder] Fw: TKR750 -Preamp Another very good choice for this application is the GLB Preselector / Preamp from Simrex Corp. I have several of these deployed on 144 / 220 / 440 Amateur repeaters and they all perform very well. They can be tuned to maximize gain or selectivity per your requirements and their support is outstanding. http://www.simrex.com/site/products/special.htm PRESELECTOR PREAMPLIFER Low cost solution to interference, intermodulation and desensitization problems. Helical Resonator Design. Preselector Specifications (pdf 63k) Preselector Example Diagram (pdf 10k)
[Repeater-Builder] Re: Simrex - GLB Pre-Selector - Preamp
n...@... wrote: ...but what is the noise figure? I'm going to ask this every time someone says they perform very well. Bob NO6B Depends on the Pre-Selectors Generation and options. The original active device could be one of a few different types. After a period in time a GasFet upgrade was offered as an option. One would have to ask what the current default active device is. If it's not a GasFet I would probably guess they do offer the option. A GasFet or Phempt is not always a desired upgrade. One of the largest US Land-Mobile (two-way) Radio Preamplifier Suppliers specifies mostly a high performance BiPolar Device in their high-level mountain top antenna distribution systems. The Noise Figure is not always the most important specification. s. Another very good choice for this application is the GLB Preselector / Preamp from Simrex Corp. I have several of these deployed on 144/220/440 Amateur repeaters and they all perform very well. They can be tuned to maximize gain or selectivity per your requirements and their support is outstanding.
[Repeater-Builder] Re: showing our age (really old radios)
Re: showing our age (really old radios) Even worse, I passed on two huge Fred Link Transmitters, one a carrier current and the mate an on air version of the same box, both on what is now the AM Broadcast Band. A ham friend of mine proudly displays his Convention Photo of him standing next to Fred Link... both in the picture look pretty darn constipated but that's how the 1970's were. The above mentioned friend just called me on the phone during my typing of this post and also mentioned he currently has two Link Control Heads he plans to use/install. Upstage that mint condition Motrac Control head another friend is using. s. Sid purvis...@... wrote: RE: Link radios. My first ham station was a Link base unit on 40 something MHz given to me by the sheriff when they got new equipment. I reworked all the tuning coils and moved it to 52.525 MHz and used it for years. Those tubes looked nice at night with the lights off. Sid. WA4VBC --- In Repeater-Builder@yahoogroups.com, Captainlance Captainlance@ wrote: Wow.. memories... A Link 50UFS low band base station.. We have one here, too... Still works. Lance N2HBA - Original Message - From: La Rue Communications To: Repeater-Builder@yahoogroups.com Sent: Tuesday, July 27, 2010 4:20 PM Subject: Re: [Repeater-Builder] showing our age (old HT's) I think I automatically disqualify myself since I dont know too much about our units. But one of the cornerstone pieces of our shop is our Link Repeater. Im not trying to one up anyone - but rather share and get into the OLD stuff with the rest of ya. I also dont think I qualify because I grew up on CHiPs and Dukes of Hazard. :) So overlook that little fact and let me ask if anyone has dabbled with this machine? (See attached) John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl.com/2dtngmn - Original Message - From: John Gleichweit To: Repeater-Builder@yahoogroups.com Sent: Tuesday, July 27, 2010 12:04 PM Subject: Re: [Repeater-Builder] showing our age (old HT's) Whaddaya mean lunchboxes don't count? I have a pair of GE Portamobile II's in the shop just begging to be recrystalled and ready to rock. If course, I was considering building those into APRS trackers or packet boxes, where everything was built inside, and all you needed to do was plug in a laptop. I dug an actual GE HandiTalkie out of the bottom of a box that was full of surplus stuff from the county. In that same lot was a couple of MX300s. -- John Smokey Behr Gleichweit FF1/EMT, CCNA, MCSE IPN-CAL023 N6FOG UP Fresno Sub MP183.5 ECV1852 List Owner x10, Moderator x9 CalEMA 51-507 http://smokeybehr.blogspot.com http://www.myspace.com/smokeybehr - Original Message From: skipp025 skipp025@ To: Repeater-Builder@yahoogroups.com Sent: Sun, July 25, 2010 7:00:36 PM Subject: [Repeater-Builder] showing our age (old HT's) Allow me to show my age ... To me, the HT-220 is/was a Xtal Controlled Ht !! Allow me to show my age... The HT here is a VHF Engineering 2 Meter Portable assembled from a kit... and it still works. :-) s. ps: Surplus Motorola and GE Lunch Boxes don't count on the bragging scale. Yahoo! Groups Links
[Repeater-Builder] showing our age (old HT's)
Allow me to show my age ... To me, the HT-220 is/was a Xtal Controlled Ht !! Allow me to show my age... The HT here is a VHF Engineering 2 Meter Portable assembled from a kit... and it still works. :-) s. ps: Surplus Motorola and GE Lunch Boxes don't count on the bragging scale.
[Repeater-Builder] Re: Recommendations for a Voter Link
Mike Morris wa6...@... wrote: The idle marker tone system was designed for wire-lines and adapted to microwave shots. Also known as Status Tone But there are ways around it. The simple method: Have a local 1950 oscillator at the voter site. It can be done with a 88mh toroid, a few resistors and caps, and a single transistor. Can't think of the last time I saw an 88mh Toroid for sale in any obvious location but I'm sure they're out there somewhere like Ebay. I found some of the newer one-chip GE Status Tone Encoders on Ebay a few months back and they were cheaper than I could have easily built them for. Have a SPDT reed relay driven by the link receiver RUS (or COR). Links can be on 420Mhz, 438-439Mhz, 900Mhz, or 1200 Mhz. ... and if you're creative some other places. The NC contact on the relay has 1950hz. NO contact has link receiver audio. Armature feeds voter card audio input. When channel is idle, card sees 1950hz and is happy. When channel is unsquelched card sees link receiver audio and votes. Wonder if the relay pole contact transition time contributes to any type of glitch, hunt, delay or erratic event that might otherwise not be there if you simply (resistance as an example) mixed and removed the Status Tone? Reed relays last a long time - I've had used ones last 12 years, and new ones last 20, but you can use CMOS audio switches if you want. CD4053 and use the diagram from an ACC RC-85 Repeater Controller as your basic guide. The GE voter performance has the Doug Hall beat hands down. The GE and Motorola Spectra Tac Voters are true Signal-To-Noise Voters, where as the LDG, earlier Doug Hall and the ARRL 2-Channel voters are not. I haven't seen a current Hall Voter Close up to determine if it's a real SN Voter but the earlier Hall versions I have like the LDG are not (true SN voters). True SN Voters don't seem to be nearly as subject to talk-off as do the lower cost voter options. But the lower cost options are quite usable. One novel trick with the LDG Voter is to use the inputs for all your repeater receivers when the controller doesn't have enough RX ports. Documentation on both vintages of the GE voter (grey paint is early, black paint is late) is on the GE LBI page at repeater- builder. Mike WA6ILQ The Spectra Tac Voter Manuals pop up on Ebay every so often as to the GE Version Manuals. If you fool the status tone decoder with a local oscillator, keep in mind the level of the Status Tone also plays into the actual performance. It's not just a tone present or tone not present function. s.
[Repeater-Builder] Re: Re-Tune a Vocom Amplifier
w5ppb w5...@... wrote: I have a Vocom amplifier model VVC100-10RF tuned at 152.375. I want to tune it for 145.450. Does anybody have tuning instructions ? Thanks ! Most of these type and model amplifiers are not easily re-tuned down to the Ham Bands. And as many Vocom Amplifiers as I have... I don't even know if they've ever provided any type of circuit diagram. I once asked Cresend for a diagram and they wouldn't provide it saying only they should re-tune their amplifier products. I don't buy or recommend Cresend any more... I would tell you to flip (sell) the Vocom and buy something already down into the Ham Bands where you can use it without grief. s.
[Repeater-Builder] Re: Re-Tune a Vocom Amplifier
Excellent... But I would not normally suggest someone go inside to try and mod the amplifier down to the Amateur Band. Things go smoother when the right people do the job with the right parts and knowledge of how to... s. Captainlance captainla...@... wrote: I've sent a few of these back to cresend, they tuned them for the ham band at minimal cost, and they have worked for years. lance n2HBA - Original Message - From: skipp025 To: Repeater-Builder@yahoogroups.com Sent: Thursday, July 22, 2010 8:21 PM Subject: [Repeater-Builder] Re: Re-Tune a Vocom Amplifier w5ppb w5ppb@ wrote: I have a Vocom amplifier model VVC100-10RF tuned at 152.375. I want to tune it for 145.450. Does anybody have tuning instructions ? Thanks ! Most of these type and model amplifiers are not easily re-tuned down to the Ham Bands. And as many Vocom Amplifiers as I have... I don't even know if they've ever provided any type of circuit diagram. I once asked Cresend for a diagram and they wouldn't provide it saying only they should re-tune their amplifier products. I don't buy or recommend Cresend any more... I would tell you to flip (sell) the Vocom and buy something already down into the Ham Bands where you can use it without grief. s.
[Repeater-Builder] Re: Controller recommendations
Joe k1ike_m...@... wrote: S-Com can be a love/hate relationship. As can be any controller... The older models did not have an RS-232 interface, so you needed to keep track of everything religiously on paper. There is/was Windows Programming Software for all the early S-Comm Controllers. Yes it used DTMF Control over the and/or over a phone line. Once you wrote the simple text scripts to program the controller the upload was fairly painless. The is an after-market Vyex Digital Audio Board Board upgrade for the 7K, which makes it the Controller and incredible machine. The DAB plays MP3 files stored on a removable MMC (memory module), the supplied firmware upgrade provides some really neat command set and function expansion... and best of all a much appreciated Serial RS-232 Port. I now do all my 7K programming through the DAB Serial Port, save/load the entire controller image or changes I need done and do a transfer to the same or what-ever 7K Controller I need to program. http://www.vyex.com/products.html BUT, they seemed to last forever. I have a few of them and they have never glitched..never. Same here, I have one of the earliest 5K's through the last of the 7K's and narry a one has ever failed. The newer S-Com controller has all the bells and whistles, including the computer interface. 73, Joe, K1ike Innovative people can park a Cat Auto RLS-1000B Link Port Switch Behind their 7K and be pretty much up with the rest of the world controller wise... less and considerations for a TCP/IP type port. http://www.catauto.com/rls1000.html cheers, skipp On 7/19/2010 9:32 AM, wd8chl wrote: Didn't see anybody mention S-Com! http://www.scomcontrollers.com/ It'll do what you want, and they just run...and run...and run...
[Repeater-Builder] Re: Controller recommendations
Joe k1ike_m...@... wrote: But does it allow you to read what is programmed in the controller? Joe Sure, I can download an entire image of the controller programming and save it. Then reprogram those contents back to the same or a different controller. Handy since I easily have 10 plus 7K Controllers (with DAB Boards) in service. S. On 7/19/2010 1:16 PM, skipp025 wrote: There is/was Windows Programming Software for all the early S-Comm Controllers. Yes it used DTMF Control over the and/or over a phone line. Once you wrote the simple text scripts to program the controller the upload was fairly painless.
[Repeater-Builder] Re: S-Com Controller Programming Software
Stephen Slider stephensli...@... wrote: Nope. It can only write to the controller. The original S-Com sold DTMF Software for the 7K. The Vyex 7K Digital Audio Board allows transfers both directions. Although I should mention the image transfer function was put in (by Dave) to help develop the DAB and was not generally intended to be used by owners or supported by Vyex, but the function and it's options are clearly mentioned in the DAB Manual and those functions do work very well. s. On 7/19/10 1:23 PM, Joe k1ike_m...@... wrote: But does it allow you to read what is programmed in the controller? Joe On 7/19/2010 1:16 PM, skipp025 wrote: There is/was Windows Programming Software for all the early S-Comm Controllers. Yes it used DTMF Control over the and/or over a phone line. Once you wrote the simple text scripts to program the controller the upload was fairly painless.
[Repeater-Builder] Re: Controller recommendations
Joe k1ike_m...@... wrote: But that is specific to the 7K controller. I have the 6K and 5K versions. To my knowledge, they cannot be downloaded. Joe Yeah but that's easily dealt with because you never forget what you have programmed and it's always right every time you program it. Mistakes are not allowed... s.
[Repeater-Builder] Re: Controller recommendations
heh-RS-232 on a ham controller was a pretty rare bird no matter what...only a few had it...til abt 7-8 years ago or so... ...so will be be another 7-8 years before we see a USB interface on all controllers? Nah we have USB now, just in the form of little adapter boxes that convert from RS-232. And those converter boxes/adapters come with cute little under-sized CD's full of drivers that may or may not work right with your OS. s.
[Repeater-Builder] Re: TKR-820 CTCSS/DCS EEPROM
Jeff, if you download KPG21D software and generate a file for a TKR-820, the file saved by KPG21D contains images of both EEproms. The 1st half of the file is the freq. data and the 2nd half is the CTCSS info.. You could either copy the data directly into Pong-prog or write it down and enter it manually.. -73, Pete N2MCI Yep, I have a TKR-820, TKR-720 EEprom file containing only the signaling information (no frequency data) saved as dpltests.r8n I put a copy of that file in the Group Files section in the/a Kenwood Folder area, sub folder for TKR-720 and TKR-820 Repeater items. http://groups.yahoo.com/group/Repeater-Builder/files/Kenwood%20/TKR-820%20TKR-720%20Repeater/ I also included a jpg image screen shot file showing the first 7 different DCS and 1 (last in the list) CTCSS entry. And Pete is right... you could do all this yourself with the Kenwood KPG-21d software. You can save Frequency, Signaling (CTCSS /or DCS) or a combination of both to the file. cheers, skipp
[Repeater-Builder] Re: TKR-820 CTCSS/DCS EEPROM
Hi Jeff, I have a few DCS TKR-720/820 Eprom files in my collection. Email me direct if you haven't got it figured out by the weekend. I have a KPT-50, the software and the ponyprog setup you have so I can help as time allows. With that software and an inexpensive EEprom Programmer easily found on Ebay... you can do a lot of neat stuff... like the mentioned. cheers, skipp025 at yahoo.com --- In Repeater-Builder@yahoogroups.com, Jeff Lavoie - KB1SPH/WQEX694 kb1...@... wrote: Ok, let me make it a little more clear for anybody that might not have understood the first message. (No offense intended Eric) A Kenwood TKR-820 repeater has CTCSS and DCS encoding and decoding built into it with an on-board controller. The configuration is stored in a EEPROM chip, 93C46 (or 93LC46). What I'm trying to do is figure out how to change the configuration without using the expensive Kenwood programmers, unfortunately this one isn't just a simple cable. I have a serial EEPROM reader/writer, so I used instructions found in the repeater-builder archives at http://www.mail-archive.com/repeater-builder@yahoogroups.com/msg63481.html to modify the configuration for the ctcss tones. Unfortunately, the person who wrote that article didn't figure out the DCS configuration. So I'm hoping that someone who has a TKR-820 already configured for DCS has the ability to read the EEPROM chip as well and send me a copy. I hope that clears it up a little more. Jeff, KB1SPH / WQEX694 -- From: Eric Lemmon wb6...@... Sent: Thursday, July 15, 2010 10:24 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] TKR-820 CTCSS/DCS EEPROM Jeff, I suspect you may be headed for disappointment. CTCSS (PL) and CDCSS (DPL) are handled differently within the radio. While the former is audio, albeit sub-audible, the latter requires a DC connection to the modulator in order to create the DCS signal at a 134.4 Hz rate. In other words the CTCSS hardware will not work for CDCSS. Perhaps some readers who have TKR-820 stations with CDCSS capability can advise you about the modifications and/or optional modules that are necessary to handle DCS. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kb1...@... Sent: Thursday, July 15, 2010 7:03 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] TKR-820 CTCSS/DCS EEPROM Ok, I'm playing around with my Kenwood TKR-820 a bit. I've found the instructions for HEX editing the channel and ctcss information after reading it from the EEPROM, and they work great. But there's nothing about DCS. I'm wiing to try and decipher how to get the DCS, but I need a look at the information from a chip that contains DCS information. Since I don't have a real programmer I can't change mine and then look at it. So if anyone has a TKR-820 with DCS in it and a EEPROM reader, it would be greatly appreciated if you are wiling to read the chip with PonyProg2000 (http://www.lancos.com/ppwin95.html) and send me a copy. Thanks, Jeff, KB1SPH / WQEX694 Yahoo! Groups Links
[Repeater-Builder] Re: MRS2000 VHF Channel element wanted
Hi! I would like to get a Receive Channel Element for a MSR2000 that will tune to 146.00MHZ range. The KXN-1086a channel element will easily operate at 146.00, you need only supply the crystal and carefully solder it to the proper inside location. A KXN-1086a that works at 150/160 MHz should be no problama down at 146 MHz. s.
[Repeater-Builder] Re: GE Mastr Pro
Todd todda...@... wrote: Does anyone have any info on moving a GE Mastr Pro repeater from VHF commercial to VHF Amateur? I am curious whether anyone has done it, would it be worth it before I end up parting them out for scrap. I also have about a dozen of the Mastr mobile of the era as well. Todd AE7V Hold that Tiger! Don't scrap the radio if you can help it. Sure the GE Master Pro will pretty much dial right down onto the ham bands with only readjustment and a capacitor or two change in the receiver crystal injection stages. And the Master Pro Receiver works just killer (great) and will still hold its own in rugged location service. s.
[Repeater-Builder] Re: Tinkering with Repeater Controller firmware - source code
I'm reversing out the source code for one of the ACC Repeater Controllers and it's not for the casual person to attempt. Was the original code done in an assembler (my guess, given the vintage)? Yep, it's all in assembly language and so far fairly straight forward. The process is taking a lot more time than I ever thought it would but I trudge on (hopefully forward). Have you asked Link Comm if by chance they have any source code? Bob NO6B If Link has it (which I probably doubt they do) I wouldn't expect them to share it... I was very appreciative of Alan and Steve supporting the ACC Controllers by supplying the last versions of firmware, copies of manuals and a replacement Eprom retrofit kit for as long as they did. And I wanted an excuse to bring my SDK-85 and ENMAC 8085 Trainers back out of storage. s.
[Repeater-Builder] Re: question for commercial radio shops
If a person whom you knew and is involved in a number of church youth camps activities asked you to program FRS frequencies into a 4w UHF HT type accepted for LMR would you do so ? It would only be for extended range at camp. If the radio power can be reduced, turn it down and program the FRS frequencies in. If the power can't be reduced, put the radios on GMRS Frequencies. Many of the Kenwood Portables I sell allow power level programming per channel so the FRS gets low and the other stuff gets the nominal rated power. FRS Radios are sold cheap at the big box stores... try to find the ones that allow you to turn off the $...@%@*% stupid roger beeps s.
[Repeater-Builder] CSI-32 (Lynnwood Washington) Repeater Tone Panel Controller Information
Jeff Lavoie - KB1SPH/WQEX694 kb1...@... wrote: Thanks Skipp, that helps a great deal. I've found a lot of useful information on repeater-builder.com over the years, Hi Jeff, Just don't buy a car from any of us and you'll be fine. I was wondering if you had any information about a CSI-32 tone panel and possible firmware upgrades. The EPROM inside has a sticker on it that says the following. 128 v4.0 6289 (I think, hard to read) © CSI In regards to the CSI (Lynnwood Washington CSI, not the Ventura CA. CSI) brand of Repeater Tone/DCS Controllers. The latest firmware version is based on the PC Board date of construction, which is most often silk screened in white ink right on the board. V4.0 was one of the last firmware versions available for most of the CSI-32 Controllers. As time allows I could check my files for firmware information but I would need to know your pc board date code in addition to all the other details. Right now I'd say the 4.0 stuff is pretty much it in regards to updates. cheers, s.
[Repeater-Builder] Re: Silver plating of cavities advice please? (pull it out, put the enamel back)
Re: Silver plating of cavities advice please? (pull it out, put the enamel back) Oh, we weren't talking about teeth... n9...@... wrote: Silver oxide unlike copper oxide remains a good conductor and does not need cleaned. However, I believe the tarnish forming on silver when exposed to ozone or hydrogen sulfide in the atmosphere is Silver Sulfide. Silver Sulfide Tarnish is not good on critical contact surfaces (as in switch contacts) and should be removed if it's causing trouble. The best use would be the high current areas around the top of the cavity and loops, also the sliding connection at the center conductor. I am paraphrasing this info from some old DB products literature I used to have. Chris N9LLO Many of us still have those old Decibel Products Booklets and related paperwork. Silver Plating is wonderful if you have it or need and can get it done at a reasonable price. Keywords Reasonable Price and of course there are ways to do your own plating, especially with example videos available on Youtube. But Silver Plating is not an in-stone requirement for a decent cavity like those used in the Motorola T-1500 series Duplexer. s.
[Repeater-Builder] Tinkering with Repeater Controller firmware - source code
Jeff Lavoie - KB1SPH/WQEX694 kb1...@... wrote: Ok, I can get you the date code tomorrow if you find some spare time to check. It's too bad I couldn't get a copy of the original code and maybe modify it myself. I like to tinker around with existing programming a bit, but I wouldn't know where to begin if I were to start from scratch. Jeff, KB1SPH / WQEX694 I have to look at whet ever the processor is to comment on modifying the code. I'm reversing out the source code for one of the ACC Repeater Controllers and it's not for the casual person to attempt. At 443 pages of disassembled source code I'd say you really have to want to do something like this. And I'm doing it for fun... Not many people want to have this kind of fun... I'm sure the source code for the CSI-32 Tone Panel is just as exciting. s.
[Repeater-Builder] Re: Silver plating of cavities advice please?
Dave dave_g7...@... wrote: Hi All, I have rescently obtained a uhf pair of cavities that are not silver plated inside (bare copper) They both have an insertion loss of 3dB In this example the 3dB insertion loss is not is not affected (to any significant value) by the lack of silver plating. If I were to get them silver plated what would the improvement be? The person/business you pay to complete the plating has an improved income. I have no idea how much it would cost but if the saving was only about 0.5dB I wouldn't bother. Don't bother... Your thoughts please? I try not to have any... Cheers Dave UZN Never watched the show and I believe it was on the UPN out here. :-) On a more serious note... you might look around for pictures and descriptions of the very famous Motorola T-1500 series of cavities often made into various combination of duplexer assemblies. They are not plated and they work very well. The insertion loss is set by the probe type and position. s.
[Repeater-Builder] Re: Silver plating of cavities advice please?
Dave dave_g7...@... wrote: Thanks for that SkippI accept your opinions but in that case why do some manufactures silver plate the insides and some don't? Cheers Dave UZN Hi Dave, Please don't accept my opinions as gospel, always try to obtain information from multiple sources following up on the stated facts for accuracy. There are two major reasons considered by many people for silver plating coil and cavity surfaces. Q and Oxidation Let's talk about both in reverse order... [pasted text from another reply post] I can't speak for the manufactures, but I think silver plating them would cut down on the chance of the cavities oxidizing over time. Silver does oxidize, just less/slower than bare copper. The environment becomes the relative pivot point in your choice to plate or nay. I have 1970's vintage bare copper cavities in clean, cool, dry locations that still look shinny/new. Many of the internally not silver plated Motorola T-1500 Duplexers are real-world examples still in active service. Q is everything if you really need it... but in this example you only need enough Q to get the job done. And in the cavities we're talking about here you should be able to obtain enough Q for the job. One of the rare examples I've really seen the obvious benefits of Silver Plating is in the field of NMR Probe Design Construction. A way off topic application for this group... but proof to me there is real merit to silver plating if you need it. In many examples for UHF/VHF Amateur Duplexer applications I'd say silver plating is not an in-stone requirement. Just beneficial if you do... cheers, s. Dave dave_g7uzn@ wrote: Hi All, I have rescently obtained a uhf pair of cavities that are not silver plated inside (bare copper) They both have an insertion loss of 3dB In this example the 3dB insertion loss is not is not affected (to any significant value) by the lack of silver plating. If I were to get them silver plated what would the improvement be? The person/business you pay to complete the plating has an improved income. I have no idea how much it would cost but if the saving was only about 0.5dB I wouldn't bother. Don't bother... Your thoughts please? I try not to have any... Cheers Dave UZN Never watched the show and I believe it was on the UPN out here. :-) On a more serious note... you might look around for pictures and descriptions of the very famous Motorola T-1500 series of cavities often made into various combination of duplexer assemblies. They are not plated and they work very well. The insertion loss is set by the probe type and position. s.
[Repeater-Builder] Re: Silver plating of cavities advice please?
Skipp, Did you ever work with Rowan and Martin?!! Doug Hi Doug, One must always keep a real sense of humor to keep from otherwise screaming at the lunatics I/we have to deal with on a daily basis. The key is to avoid giving the real lunatics your home or cell phone number. :-) s. PS: I do enjoy listening to Ernestine the Telephone Operator skits on the XM Satellite Radio Comedy Channels. Though just a coincidence... I think.
[Repeater-Builder] Recrystal MSR-2000 Channel Elements (and a guacamole recipe)
Recrystal MSR-2000 Channel Elements Path_Finder.Geo kb1...@... wrote: Hi everyone, I am going to post this message here because batlabs didn't approve my post. Apparently it's too harsh to tell people, PLEASE DO NOT TELL ME TO HAVE SOMEONE ELSE DO IT. Hi Jeff, Apparently you do not play the BatLabs Game very well? I'm sure you'll survive with the ever so perky bunch over here. I am looking for information on how exactly to re-tune a channel element for a MSR repeater. I've seen instructions as far as what to adjust on the element itself, but what I really need to know is; what equipment is required, how to hook that equipment up to the channel element, and what to look for while adjusting the channel element. The transmit channel element is best adjusted for frequency center by using a Communications Service Monitor setup to sample (off the on-air signal) read the main carrier channel/frequency. The simple way to set the IDC Control/Pot is to set the Transmit CTCSS (PL) Tone deviation to about 750Hz. In a stock MSR-2000 the repeat audio level is then set using the level pot on the Squelch Gate Module. If you don't have access to a Service Monitor, a decent Frequency Counter will at least let you net (adjust) the frequency to F-center (on the desired frequency). If you move the transmitter more than say... 500 kHz from its last alignment location, you should repeat the Service Manual Alignment steps on or near the new frequency. The Receiver is a different animal. Take the Receiver frequency and add and/or subtract the receiver IF frequency (most often 10.7 or 10.8 MHz for the VHF Receiver). The formula you use depends on your receivers IF Frequency and Injection Chain, which translates to which side of the IF the multiplied crystal frequency ends up on. In your example it's probably F-frequency minus the IF Frequency equals the multiplied Channel Element injection frequency, which is what you want to set/align. Put a X1 Scope/Text Probe on your Service Monitor (or Frequency Counter) Antenna (Low Level RF) Input and place it down onto/near the receiver circuit board. You can also use a decent quality frequency counter if you're more careful. At some location on or near the board you will be able to monitor and measure the output of the RX Channel Element Frequency, then set it for the expected Injection Frequency. As an example: A receive frequency of 151.625 MHz minus a 10.7 IF frequency equals 140.925 MHz. Sniff around the receiver board until you observe a signal in that area, then net (adjust) the channel element frequency to the expected 140.925 F-center location. If you can't find the expected frequency you might run the numbers for a 10.8 IF Frequency and sniff around 140.825 for the channel element injection frequency. In both the above examples, a X1 (times-1) Scope Probe or something similar is handy to use. If you can't get/find a signal, make a short antenna probe by clipping a small length of insulated regular wire onto the end of the probe. The end of the wire held by the Scope Probe jaws should obviously be stripped bare. Try not to allow the sampling wire and/or probe to directly contact/short any of the exposed metal parts on the receiver board. Now I realize that I need a new crystal as well, and I realize it can all be done professionally with temperature compensation. Yeah but in many cases professional is a lot more expensive than it really has to be. But what I want to know is how I can do it myself just to get started and make sure everything is going to work the way I want before I pay out big bucks to have it all done the right way. I have an extra set of channel elements, so playing around with one set isn't going to affect having the other set done professionally if I mess something up. For me there are two regular places to order crystals. The first is International Crystal Manufacturing, always high quality but you will find the pricing a bit steep for any casual crystal/channel element work. The second location for me is Bomar, where I pretty much buy all my channel element crystals. Their quality, pricing and wait time is in my opinion more than fair. Their only down side (to me) is their $50 min order amount. So you might need to order a few extra crystals to make an order amount. Not a problem if you think ahead or pal-up with someone else to place an order. I call Bomar with a Visa Card in the other hand, tell them I want Crystals for Mitrek/MSR-2000 Channel Elements KXN-1086 and KXN-1088 types. There are other MSR Channel Element numbers you can use, but the above model numbers are the most popular and should be interchangeable with anything you might have. At a price of about $15/$20 per crystal (last time I had some cut) I order at least 4 crystals to make the min order amount. Wait the normal time (they do have rush service for more $$)
[Repeater-Builder] Re: Hamtronics Repeater Boards?
vk4jrc ra...@... wrote: I have ordered some Hamtronics UHF Tx Rx PCBs to use for building a repeater. I'm a big fan of using Hamtronics Products... yes, there are often lower cost surplus commercial radio choices for a more complete end result. Those who demonstrate patience, which took me decades to get a decent handle about applying to myself end up with a very satisfying end result. http://groups.yahoo.com/group/Repeater-Builder/photos/album/1157128983/pic/list Not to mention the wondeful hands-on experience and exposure you receive actually building things. Are there any other suppliers who make a similar product that I could buy and make a comparison for performance? Or, should I just stick with the Hamtronics boards, alone? Sure, Maggiore Electronic Lab offers similar products, of which I'm also an owner and fan of... http://www.hiprorepeaters.com/ Cheers, Jack. VK4JRC Good luck with your project Jack, post pictures of the results when you're done. cheers, s.
[Repeater-Builder] Re: VHF REPEATER USING DELTA or RANGER
tomnevue w...@... wrote: Has anyone made a VHF repeater using 2 Delta or Ranger radios? Were the results OK? Any unexpected problems? Tom I use a pair of Low Band Rangers for repeater service and they just keep going. I have a macro controlled timed fan on the transmit unit, turn down the power to about 75 watts and generally beat the snot out every one of them since the mid 1980's and they are still 100% operational . The Low Band GE Ranger is one heck of a great radio. In most sane applications you'd be hard pressed to kill one. Moving a LB unit up onto 6 meters is a $%^^(* pain but it can be done. cheers, s.
[Repeater-Builder] Re: carrier operated relay project
Re: carrier operated relay project Greetings, You forgot to add the earth people part. Hi Manny, Can anybody help me to make a makeshift repeater, I need a schematic diagram for carrier operated relay or COR for two radio transceivers to be converted into a repeater. Thanks to anyone who can help on this. Manny , ( mrj12...@... ) The carriers operated relay circuit is pretty generic. The connection to the receiver (radio) and the audio interface are the portions of the project that require the most attention. And the above issues are tied to the specific radio model and how easy or hard it is to obtain (or derive) those connection points. For a repeater, you could simply sample the speaker audio, use it to turn on a basic cor circuit along with an audio path connection for the transmit radio. But the circuit won't be the most user friendly operation because the first part of your transmission is almost always chopped off and silent periods also drop the transmit signal. But the circuit is simple and easy to do, plus it doesn't normally require you go inside the radios to make a connection. The more common methods include getting inside the receiver to obtain and interface a COS/COR logic wire/circuit and what ever method you choose to obtain audio for the transmitter. So the specifics past a generic relay COR circuit kind of depend on what radios you use for the repeater. Members of the Repeater Builder Group have interfaced most of the common radios into repeater hardware so you need only let us know what radios you plan to use. We'll be happy to provide you with abuse $%#*@ ... I mean additional help. cheers, s.
[Repeater-Builder] Re: 6 Meter Heliax - Hard-line Duplxers Piston Caps
Re: 6 Meter Heliax - Hard-line Duplxers Piston Caps A recent Email conversation with another Group member... I had recently revisited the subject of the Hard-line Notch sections Duplexers followed by a few Google Searches. The results returned the classic Texas Duplexer and a number of other clone and next-step projects. However, One England/UK Ham had dealt with the piston capacitor problem by making his own and sharing that information with the US Amateur whose web page I found the initial pictures and description of. You simply need to search Google in more detail to find that page. When I get back to my office computer on Friday I can try to forward the URL or duplexer info to you if you direct Email at that time. There's a lot of new material on the web regarding 6 meter duplexer projects so a revisit is well worth the effort. There are other methods to construct most every section of the original design, some are major improvements. I ended up saving about 6 different web page sources full of wonderful ideas. They're still on the web if you search them out... s. tahrens301 tahr...@... wrote: Hi Folks, Well, they are complete, but there seems to be a problem with the transmit side 'cavities'. The variable capacitor from the center of the SO-239 to the center conductor gets extremely hot. I'm running about 70 watts out of the PA, and the devices that I used are identical to what was shown in the construction article. Just wondering if anyone else has built these, and did you see heating as well. (the first piston trimmers I used arc'd right thru)! Thanks, Tim W5FN
[Repeater-Builder] Hard line duplexer piston cap info
re: Hard line duplexer piston cap info Of course I couldn't easily find the 6 meter hard line duplexer piston capacitor construction information while typing my last post... and one minute later it turned up: http://k5jmp.us/Six_Meter_Heliax_and_Helical_Duplexer_info/6m_duplexer_page.htm Credit is properly given to Brian - G4UTM for the roll your own piston cap that works very well. For the http://www.gb3fh.eclipse.co.uk/technical.htm repeater system. cheers, skipp
[Repeater-Builder] Re: Inline coax connector style impedance matcher
kq7dx kq...@... wrote: Dear Group, Stop calling me Dear... people will get nervous Somewhere I saw or heard of a inline coaxial impedance matcher. It looks like a barrel connector but it actually has an adjustment on it for adjusting or trimming SWR between devices. It is placed inline with the coax ,between a driver and amp or between duplexer cavites etc, and adjusted for 50 ohms in instances where the coax length is not optimum. I thought Digikey made them but cant find it. If anyone knows about these and where to get them let me know.. 73 What the impedance matcher looks like and how it works is based on the frequency/band of operation and where it will be placed. The small or barrel type I remember were mostly made for the high end of the HF Bands. You can call the impedance matcher a number of different names like Z-Match or Antenna Tuner. The type of Z-Matcher most of the people on this group are probably thinking about was popularized by the GE Land Mobile (two-way) Radio folks, mostly for use with their repeater and base station equipment. And there is a web page with that information if you felt inclined to build something similar. http://w4zt.com/zmatch/ Companies like Telewave and TX/RX who make duplexers and cavities also sell similar matcher products. And we have seen them pop up on Ebay from time to time. s.
[Repeater-Builder] Re: Sinclair Tx Multicoupler model CT2_208
Hi Doug, Yeah, it's probably quite usable on the ham bands... but keep in mind it's a hybrid unit, which normally assumes two fairly close spaced transmitters. You could separate the isolator/circulator parts and use them in individual applications without the hybrid... unless you need to couple two very close spaced transmitters. cheers, s. --- In Repeater-Builder@yahoogroups.com, Doug ap...@... wrote: I have come across a TX Multicoupler Model CT2-208 frequency 148-174 mhz. The unit is equipped with one tunable hybrid, and four single isolators with terminations. Each circulator has a tuning adjustment on top. Looks like a Johannson capacitor. One isolator in each pair is marked as 118 - 174 mhz and the other 148 - 174 mhz. Is it of any use in the ham band and if so how would one go about tuning it... Neither Sinclair's site or google were any help. I think it is pretty old.. The isolators make the unit pretty heavy. Can anyone shed any light on the unit?? TIA DOUG VE5DA
[Repeater-Builder] Re: tone panel deal of the moment
x.tait.tech x.tait.t...@... wrote: US sales only , typical, Marcus Hi Marcus, If you became friends with some of the US Based people on the group... over time building a rapport, some of us do on occasion offer to help. The problem is... many of times I've helped someone outside the US Deal with Ebay Shipments it's like a large water dam bursts and they flood me with excessive shipping work ... There are companies that can help deal with outside US Shipping. ... and there are some countries that seem to go out of their way to make shipping packages a real pain in the pazzoo. The global market place isn't always so easy to deal with. cheers, s. If you have any interest in playing with a Repeater CTCSS Tone Panel... here's the deal of the moment. Ebay Item 220627865813 COM SPEC REPETER TONE PANEL Starting bid: US $20.00 If nothing else you could tack it onto the disc (in some cases even the low level recorder) output of your scanner for a visual of the tone in use. Hope someone gets the great deal... s. And no, I don't have anything to do with the auction... I'd buy this auction if I didn't already have one (actually more than one) of these units.
[Repeater-Builder] Re: tone panel deal of the moment
I'm not sure I understand what the problem shipping overseas is. I've done a fair amount of eBay trading myself, and it's never been more than paying the postage for whatever the destination is, and a single page form declaring what the item is, and it's value. And many times, I haven't even been required to fill out a declaration form. I do virtually all my shipping via the internet, with pick up from my front porch. In the Ebay world, some US Sellers believe a majority of their inbound scam and proof of delivery - tracking problems are related to some (not all) out of the country buyer/seller sources. Are there some countries that trigger a more difficult process? Yes I've shipped to Australia, New Zealand, South Africa, South America, Israel, and all over Europe including some of the former Soviet block countries and it's been no problem at all. Some Ebay Sellers don't want to bother with the out of country sell and ship experience. ... or in reality make the effort. In buying stuff, I'm receiving items from Hong Kong and Israel faster than I get it from across the state. Mel - WA6JBD Speed of delivery... across the state versus out of the country? The above hasn't been my experience but I can't remember recently not receiving a purchased item. Feedback ratings are a relative indicator ... s.
[Repeater-Builder] Re: shipping out of the US
If you're an account holder with UPS, International Shipping is not a chore - just filling in one carbon piece of paperwork, and stick it in the clear envelope. Viola! UPS and Fed Ex accessibility can be cumbersome at best in non metro areas of the country. US Mail is the most available method to the US masses and not all receiver locations guaranty real proof of delivery. s.
[Repeater-Builder] Re: Death of a Service Monitor
Ted Bleiman K9MDM - MDM Radio k9...@... wrote: Idiotic waste of time and band width So I broke down (no pun intended) and had a look. Really sad to see that happen while thinking I know where I could have gotten that Service Monitor Refurbished. s. From: Joe k1ike_m...@... Subject: [Repeater-Builder] Death of a Service Monitor To: Repeater-Builder@yahoogroups.com Date: Wednesday, June 30, 2010, 10:36 AM Worth watching if a service monitor ever caused you frustration. http://www.youtube.com/watch?v=3nXbBS3lVXU
[Repeater-Builder] tone panel deal of the moment
If you have any interest in playing with a Repeater CTCSS Tone Panel... here's the deal of the moment. Ebay Item 220627865813 COM SPEC REPETER TONE PANEL Starting bid: US $20.00 If nothing else you could tack it onto the disc (in some cases even the low level recorder) output of your scanner for a visual of the tone in use. Hope someone gets the great deal... s. And no, I don't have anything to do with the auction... I'd buy this auction if I didn't already have one (actually more than one) of these units.
[Repeater-Builder] How to Disable - Block - Remove Yahoo Trending
How to Disable - Block - Remove Yahoo trending If anyone else on the group using Yahoo (Classic) Email is annoyed enough (me being very civil about the subject) by the scrolling Yahoo Trending Display, you can stop it by plugging the no-script add-on into your Mozilla Web Browser. It's possible to regain your composure... maybe not your sanity or what's left of it. cheers, s.
[Repeater-Builder] Re: Coax shielding
Ian Wells kerin...@... wrote: Currently I have no filters between the link transmitter and its antenna. The next question in our Top Twenty Radio Hits - Countdown List is do you have any spare or available cavities to try a few things we might suggest? Selection B Are any extra or available to test with Cavities configured as band-pass, notch or some combination there of? s. Selection C Would you know the next winning 6 numbers for the Wednesday Evening California Supper Lotto? forget Selection C
[Repeater-Builder] Re: Converting the Kenwood TKR-820 to use with D-STAR
John j...@... wrote: My conversion project is at: http://k7ve.org/blog/2010/06/converting-the-kenwood-tkr-820-to-use-with-d-star/ 73 de K7VE Very nice project... the only thing that drives me crazy is: If you haven't guessed I used a piece of CAT-5 cable between the connectors. I hate CAT-5 (CAT-6) cable for jumpers like this... although in the real world I suppose there's nothing super wrong with it. In fact it's probably better than a lot of the other types of el cheapo wire I see used. Just to see the insulation creep up the wire when you heat it with a soldering iron. ... Monday morning pre-coffee opinion spouting. s.
[Repeater-Builder] Re: Coax shielding
kerincom kerin...@... wrote: Hi guys .I am just wanted to confirm a question on coax shielding . Simple answer... It's there and never seems to behave exactly how you would expect it to. With 2-10 watts transmitting through rg213u could RF be escaping that could cause desensitization to other radios. RF can escape through some types of hard line (believe it or not). There always will be local area RF around, just a question of how much is coming through/from the coax braid and what if any grief it may be causing. If you're working at the 2 to 10 watt (what many of us assume is a fairly low) power level and you've got desense gremlins, smart money says you probably (also) have other or additional issues to deal with. The repeater I have setup uses 9 meters of heliax from the main diplexer to ant and rg213u from the link radio to its antenna. Nothing wrong with RG-213u especially when compared to other possible choices like someone using RG-58au. Just a question of loss per length and your preference with the end result values when you use/install it. I am finding I am getting problems with the link transmission interfering with the repeater rx. The link antenna is a yagi 3 meters above the ground and the main repeater antenna is 6 meters above it. So do some testing... put a termination (dummy load) on the end of the feed-line (regardless of the type you're using) at the Link-Yagi end. See if the problem goes away when you've got the Link Radio (transmitter) working at full power into the test termination (load). I am currently trying band pass cavity on the receiver rx or band pass/band reject diplexer with some success but I am wondering if the rf escaping from the cable is causing problems inside the repeater shed even at a low wattage. The proper type and placement of cavities will help, but you should first consider the Link Tx Termination Test I mention above. You don't yet know where the problem really originates from and you don't mention what type of repeater receiver you're using. Should we assume it's something of decent quality and that you have it properly protected. And what's the repeater transmitter doing when the link is active? Do you make the classic mistake of tie-wrapping the feed lines into one big bunch? I am definitely changing the rg213u to either rg223u or lmr400 as it is only on the link radio and shouldn't have any effect on the repeater's operation. Please... If you feel you must change the feed line, don't use any LMR type of coaxial line or you'll be wasting your and our time with additional problems. LMR-400 is not good coax to use in and around duplex (repeater) radio or any high adjacent RF environments. Has anyone else had the same sort of problem where the rf energy leaks out of the cable in the shed and causes problems to the repeater and they had to upgrade the link cable to 100% coverage cable You're not yet sure that's the problem and I'll bet the coax shielding value is not the large problem contribution you think it is. We'd need to know more about the radios, antennas, power levels, receiver and transmitter filtering (what we call Duplexer) or pre-selectors and notch cavities you might have around. Even though you're running RG-213u, it's not the best but when applied in modest length runs it's not the train wreck you might think it is. And you're on the bottom side of the earth in Auzzie Land so we have to flip the computer screen upside down to read your posts, but that's relatively easy. :-) Thank You, Ian Wells, your turn, s.
[Repeater-Builder] Re: Piston Trimmer Voltage Rating
Instead of piston trimmers you might want to try ARCO padders (postage stamp size that can tolerate higher levels of rf current) or small air variable capacitors. I have nfound both at reasonable prices at this site: A generic statement that has merit in this subject Q is everything and the Q of an Arco cap (padder) is probably no where near as good as a decent piston cap. Ebay provides the occasional deal on nice piston caps. If you're not at a critical current location, the A49 piston caps in the following sale ad work for some applications. http://www.hamtronics.com/sale.htm s. http://www.danssmallpartsandkits.net/ 73 and aloha, Eric KH6CQ --- On Sun, 6/27/10, Tim tahr...@... wrote: From: Tim tahr...@... Subject: [Repeater-Builder] Piston Trimmer Voltage Rating To: Repeater-Builder@yahoogroups.com Date: Sunday, June 27, 2010, 11:18 AM Â Hi folks, Am just finishing up the 6 meter heliax duplexer project, and am getting some pretty good numbers. (3 'cans' on each side, 90dB notch about 1.2dB 'pass' attenuation).. Anyhow, I used some Johanson piston trimmers that I had, but evidently they are a bit shy on the working voltage rating, as the one closest to the transmitter (80 w, @53.15) didn't quite cut the mustard! A nice arc hole in the piston. Anyhow, was wondering what the working voltage is for these guys. Guess I need to look around for some substitutes. Thanks, Tim W5FN Utopia, TX
[Repeater-Builder] Re: Harmful Taxing
Kevin. ZL1KFM spar...@... wrote: Plan was to build 3 remote RX sites and feed it back to the main site (4th RX) and expand the coverage. However our MED (Your FCC) decided to charge for every repeater in the country, this included Amateur repeaters. Tax revenue crazy Governments don't realize how much damage their plain greed does to innovation, education, creativity and growth. s.
[Repeater-Builder] Re: Astron HELP!! (35A)
You Emailed me direct, I replied and said I'd help you along with some instructions... so guess yes. Someone did answer you (me) and it's now your turn to reply back to me after reading my reply. s. kd8dey kd8...@... wrote: --- In Repeater-Builder@yahoogroups.com, kd8dey kd8dey@ wrote: Howdy y'all. I came across the repeater builders website looking for information on the Astron 35A. I am in my 4th quarter at ITT and just started Devices 1. I just received a non working 35A from another ham for use as Study material for our electronics club. Looking at the 4 different schematics available I Believe that we have the one based on the 1991 schematic. So far we know that the MCR225 is toast. There was enough of it to get a partial number off to help us guess that it was the 1991 version which is the only one to use that specific part number. Also on the cabinet mounted TIP29 there is a brown lead that I believe is coming from the emitter to the top of a resistor sticking up on its end. That resistor is also toast and I am guessing the tip29 along with it. I am not sure if that is the 2.4 ohm resistor that is omitted in some of the other schematics or not. Its too burnt up to tell any color codes. I am curious as to what would have caused this kind of failure along with suggested replacement parts numbers. I also need verification as to the Identification of the mystery resistor. Any help would be appreciated. 73 Guess not
[Repeater-Builder] Simulcast Information on-line
For those of you who'd like to see a few different examples of various Simulcast Systems explained. http://www.simulcastsolutions.com/case-studies.htm
[Repeater-Builder] Re: Motorola MTR-2000 Repeaters
tracomm trac...@... wrote: MTR-2000 repeaters are notorious for issues that require a power reset, less often with the latest version of firmware, but still require reset, there is a service bulletin on this. CJD Does the Service Bulletin provide a real world fix? ... or some type of work around? s.
[Repeater-Builder] Re: Motorola radios and Zetron 37 (reset timers for frozen controllers)
Re: Motorola radios and Zetron 37 (reset timers for frozen controllers) tracomm trac...@... wrote: This is a regular issue with many controllers, especially Trident Raiders several Comm Spec units, and Motorola MTR-2000 repeaters. I have yet to find any type of relatively complex software driven uP in controller operation that didn't freeze or fart (lock) up at some point in time. One would hope the mfgr hopefully included some type of dead-man or equivalent software-hardware reset timer. Years ago Comm Spec supplied a small board that reset power to the controller to eliminate the problem. For the TP-3200 Tone/DCS Panel... and they were smart/nice enough to provide the timer daughter-board as a free retrofit. We installed power reset modules on all our repeaters, every 24 hours, The Comm Spec supplied timer cycled more frequent. power is reset to the entire repeater, usually about 3:00 am. Is/was there any reason to cycle power to other portions of the repeater hardware? Joel ag4qc@ wrote: We have 2 repeaters that are more or less the same. One is on 2 meters and the other is on 440. They both exhibit the same problem, they lockup after a while and then need to be power cycled. Q: The repeater hardware (radios)? the Zetron Controller? both? Did/do you test to find out what is locked up (not working)? They ran for years without issue. We have the Instruction manual for the Zentron controller, but nothing on the radios. Joe Loucka -- AG4QC You shouldn't need much in the way of manuals to do the basic go, no-go testing. A received signal should indicate on both the RX Radio and the Zetron front panels. The Zetron should indicate valid tone/dcs codes and the Tx activity should be indicated on both the Zetron and TX Radio front panels. Step two depends on the answer(s) to the above question. s.
[Repeater-Builder] Counterfeit ICs
Hello again Sailors,
A friend sent this information to me and I thought it's well
worth passing along. I've removed some of the company name
specific portions.
Re: Counterfeit ICs
[pasted text below]
We had a meeting about this last week. The supply chain folks
were given some pretty strict guidelines on source of supply
and validating real parts.
One of our sister companies uses the xx chip for an XXX amp in
a xxx product. They suddenly had a zero percent pass rate on
temperature cycling...every single IC failed when it was taken down
to cold temperatures...catastrophically...it did not come back to
life. The company's internal sleuths discovered something peculiar
- the date codes on the failed ICs was 2008, but On Semiconductor
says they never built parts with date codes after 2006no new
parts have been made since 2006.
It was via the Sonoscan acoustical imaging technique that they were
able to determine some real differences between the new ICs and
genuine old ICs in the builds from the early 2000sthe ICs were
fake.
The fake IC process itself is fascinating. There is a demand for
old ICs and counterfeiters are more than happy to comply. Old
consumer products go to whatever country, and the solder melted
over a bonfire. Removal of the ICs is done by banging the boards
on the inside of a tin can. ICs are gathered together, and cleaned
in the river to get rid of campfire debris. If the part number is
identifiable, they'll sand off the top printing, spray on a coating
of blacktop, then re-print with a newer date code. In some cases,
they re-plate the leads to make them look new again.
This is if you're lucky - you actually get silicon die inside that
performs the function you want. Sometimes, they're brand-new plastic
packages, but with no functioning IC in them...those counterfeiters
are banking on you putting in an inventory for repair, then not
using them for a long time...then you'll forget who you bought
them from.
The campfire/banging process does damage to the bonding inside the
ICs and makes them fragile. It often introduces microfractures to
the housing, which will allow moisture ingress and the chip will
fail after only a few years.
The supply chain manager of xx company went on a hunt to
determine how these things get into supply. It's almost always
when someone's desperate for a part that's not in production any
more. They ended up giving us a list of known good suppliers who
have solid supply chains. Tyme Electronics, Newark, Future,
Digi-Key and TTI (parent company of Mouser) were all on the
good list. All of them have supplied fake parts, but once
they figured out how they got them, they fixed their systems.
Q components, Quest Electronics, Jameco, Richardson, and RFParts
have refused to acknowledge the problem, and for part numbers in
the catalog which are known to be obsolete, nearly all the
supplied parts measure counterfeit. We're allowed to purchase
from those suppliers, but only after jumping through a lot of
hoops...the part must be in current production, and the supplier
must permit us to inspect their sourcing process and we have to
perform inspections on every delivered lot.
Here's the article that they referred us to for how to identify
fake parts:
http://www.circuitsassembly.com/cms/component/content/article/159/9937?fbc_channel=1#{%22id%22%3A0%2C%22sc%22%3A%22http%3A%2F%2Fwww.facebook.com%2Fxd_receiver_v0.4.php%22%2C%22sf%22%3A%22loginStatus%22%2C%22sr%22%3A2%2C%22h%22%3A%22loginServer%22%2C%
And yes, all of the xxx company's Operating Companies (xx)
that work in electronics have the acoustic imaging system by
Sonoscan.
Here's Sonoscan's original article detailing this hard-to-identify
blacktop that thoroughly emulates the original IC package
(caution - 10 megabyte file, don't download unless you're on a
high speed link)
http://www.smttech.com/pdf/Engineered-Blacktop-Material-Analysis-SMT-Corporation-PP-08-27-09.pdf
A more brief article on the new blacktopping material:
http://www.idofea.org/new_site/index.php?option=com_contentview=articleid=97:new-counterfeiting-blacktopping-technique-threat-is-a-qc-game-changercatid=29:generalinfoItemid=3
A more general article on how to identify counterfeit parts
(including an X-ray photo of a package that had no die in it):
http://www.empf.org/empfasis/2007/Nov07/tech_tipsr-1107.html
When dissected, what they found is that the die attach
inside the package was severely compromised, with only 25% of the
die actually thermally in contact with the package. With enough
heating/cooling cycles and/or vibration, these chips were destined
to fail prematurely even without thermal cycling. The thermal
cycle simply allowed their earlier discovery.
Other interesting things that have been found: so-called new old
stock parts with more legitimate date codes - that were still
counterfeit.
They also cautioned you
[Repeater-Builder] Re: Quantar Simulcast Issue
wmhpowell w...@... wrote: I'm looking for some Quantar engineering level help re: an interesting simulcast issue. Does it have to be Quantar? I live in an area where I can hear several of high band our simulcast Quantars. The whole thing was installed and set up by Motorola including GPS stabilized time bases. All that and $3 can sometimes get you a decent latte. I'm monitoring with a true monitor: wide band IF and little limiting. When the dispatcher drops a dead carrier I hear little in the way of hetrodyne or grunge as it should be. Hopefully meaning the carriers are close to each other and not moving around a lot. However, when the dispatcher drops alert tones I hear a hetrodyne that decreases in frequency over the duration of the tone. During the tones present or after the tones go away? My guess is that the tone is somehow pulling one of the VCOs in a Quantar exciter because of a lack of DC restoration in the modulator: a capacitor is charging and slightly shifting frequency. Why would you guess that? I consider this to be abnormal and undesirable behavior - especially in a system of this caliber. How about any Simulcast System... I haven't done any field tests yet. I suppose I can set up 2 service monitors: one to receive in the AM mode and the other to provide a reference carrier and then send tone to each transmitter, in turn. That, at least would let me isolate the problem to one, two, ?? radios. Not where I'd first go/test... Has anyone else experienced a problem like this? Yes Any Motorola engineers out there? Can I be an Authorized Kenwood Service Station and Dealer Instead? Or is a retired from Motorhead Field Service person OK? Our local tech is also baffled so I'm reaching out for ideas. Thanks, Bill Powell Keyboard player for Lynyrd Skynyrd? Getting serious for a hopefully brief moment... How is the tx audio making it's way to the repeater/base stations? Have you checked and compensated for group delay on those paths? Got milk? s.
[Repeater-Builder] Hard-Line Filter pager filter construction web page.
re: Hard-Line Filter pager filter construction web page. This is pretty neat'o http://www.vk5zd.com/PagerFilter/Filter.aspx enjoy, s.
[Repeater-Builder] Re: GE MASTR Professional Equipment
To All: I am going to get completely away from MASTR Pro equipment. If anybody wants anything, contact me off net and I'll see if I have it. Cost very cheep plus shipping. Anything not gone in three weeks is going to the trash. Fred W5VAY That's a shame Fred later down the road you might realize the GE Master Pro Receiver is one heck of a decent unit and still quite usable. The transmitters a bit of a power pig because most of them have tubes in them... but again the receivers are still quite killer (good). Hopefully someone close to you will realize the receivers are well worth having and quite usable for a current project. cheers, s.
[Repeater-Builder] Re: GE MASTR Professional Equipment
Fred Seamans seaman...@... wrote: Skip: Yes, I Know; The first radio system I designed had 74 Repeaters and over 150 mobiles with some microwave interconnects. I have run out of space, and now I have all MASTR II and Delta's. Fred W5VAY There's a simple fix Fred... move to a bigger place and start bringing in overseas shipping containers. I'd start with the 20 footers as they're easier to move in place. :-) s.
[Repeater-Builder] Re: DDRR Antenna on a tower
Re: DDRR Antenna on a tower Keep in mind the DDRR Antenna is a reduced size vertical polarized antenna and the Squalo Ho-Loop are normally considered full or standard size loop type antennas that are horizontally polarized. DDRR Antenna mounted on a tower? Only if there were no other decent options. Maybe, but I've never run into that situation. Kris Kirby k...@... wrote: That would definately earn you the hammie award, which is a downward look from the commercial guys. Don't want the commercial radio guys looking down at me any more than they already do... Also, DDRRs are notoriously touchy about the local environment and tuning. Expect a 500KHz wide 2:1 and if anything changes within a wavelength or less of the antenna, it's tuning will change. Possibly why they are normally supplied with a radome. In short, it's an antenna best used as a mobile, where you're likely to be able to keep it in tune. Hasn't been a problem so far, but I could be the exception to the rule book. I'll Keep the Kreco and Sinclair LB Antennas in place on the tower. thanks, s.
[Repeater-Builder] Re: Icom Repeater Eprom Reprogramming
Re: Icom Repeater Eprom Reprogramming It was probably me... but I didn't and don't charge for doing them/it. I can do it, but right now you have to be very patient with me as I'm up to my backside in alligators and I don't even have a swamp nearby. Meaning I'm working long hours on a major project that needs to get done on schedule. There is more than one Icom Repeater Controller Version with Eprom contents storage. Whom ever reprograms your Eprom will probably need to know what the CPU is and the size of the last Eprom that worked. I know for a fact that more than one size/ type of Eprom was used. What happened to Icom Customer Service? Remember I'm a Kenwood Dealer... :-) but I'll still help you. So Email me later/direct if no one else offers to help any sooner than I can get back to you. cheers, skipp skipp025 at yahoo.com Joe k1ike_m...@... wrote: Henry, I have an RP-3010 that someone reprogrammed the callsign for me. That was back in 1999, he may still be around and willing to program your EPROM possibly for a small fee. Email me direct and I'll see if he is interested, if his email address is still good. The original ICOM controller is very, very simplistic and does some annoying things. I would not waste my time reprogramming it. There are some inexpensive controllers out there that would run circles around the stock ICOM controller. 73, Joe, K1ike On 6/9/2010 12:43 PM, k4...@... wrote: A friend brought over an Icom rp-1510 that he had bought and wanted to change the cwid call. It looks like the call may be contained in the 27256 EPROM. Since the EPROM was in a socket, so I unplugged it and read the data. I could see nothing that looked like a callsign, so I suspect it is probably binary. Does anyone have any info on re-programming the callsign? I can burn the EPROM but need to know how the data is arranged. Thanks Henry
[Repeater-Builder] re: DDRR Antenna on a tower
cruizzer77 atlant...@... wrote: This DDRR antenna is also new to me but space-wise it is even smaller than the Squalo so definitely worth considering, Keep in mind the DDRR Antenna is a reduced size vertical polarized antenna and the Squalo Ho-Loop are normally considered full or standard size loop type antennas that are horizontally polarized. And most mobiles working FM are vertical polarized signals. ... especially because I wouldn't want to try the squalo if the majority says it won't perform as expected. It should preform exactly as we expect it would. But not as you might desire it would... Would you use just one of them even though it's on the side of the tower or 2 or 4 of them around? Squalo /or Ho-Loop rotated out of the normal mounting plane and installed on a tower? Zero or not Your intention of possibly mounting a rotated Squalo or Ho-Loop is a popcorn fart. They are normally considered a standard size loop and by the time you get one installed you've practically reached the size of a standard 1/4 ground plane. So avoid the obvious waste of time... and money. DDRR Antenna mounted on a tower? Only if there were no other decent options.Maybe, but I've never run into that situation. s.
[Repeater-Builder] Re: WTB transistor M9887
I'm sending him one... it's taken care of... thanks s. kevin valentino kevinvalent...@... wrote: That transistor alone is gonna cost about $40.00 If someone has a rig for cheap, way to go in my opinoin. If I had one I would send, unfortunately gonna pay mot $ --- On Thu, 6/10/10, rfburnz rfpo...@... wrote: From: rfburnz rfpo...@... Subject: [Repeater-Builder] WTB transistor M9887 To: Repeater-Builder@yahoogroups.com Date: Thursday, June 10, 2010, 11:08 PM Â The M9887 is a tripler transistor in the UHF Mitreks and MSR2000, I need one and wonder if anyone has one (new or used) - I just don't want to buy a Mitrek becasue of the shipping, but the MSR exciter is small enough I would purchase the entire module if someone has one, please let me know There is no known sub so please don't suggest anything else. This is a weird transistor as it has the Emitter in the pin that is normally a Collector pin in similar looking packages. Thanks in advance!
