RE: [Repeater-Builder] Duplexers
Has anyone mentioned band-pass cavities? One on the RX side could be enough and one more on the TX would do it for sure. There're some for 220 for less then a $100 on ebay right now. This might sound off the wall but I once saw a DB4021 UHF band-pass cavity tune up quite well on 2 meters!!! Only about .6db insertion loss on 2 meters. So if you have a VHF or UHF band-pass I would try sweeping it with the resonator in a few different spots and see if you find any harmonics near your target frequency. And I would only do this on the RX side. That UHF cavity tuned to 2 meters did get warmer then the other db4001's, probably an impedance issue. Forgot to mention the swr on that cavity was about 1.3 . So is this the worst practice ever, or what happened? ~Ross -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Mackey Sent: Monday, August 30, 2010 4:44 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Duplexers Our club was recently given a 220 repeater. We have two seperate antennas. We do not have a duplexer. My question is do we have to have a duplexer? How can we keep the transmitter from desensitizing the receiver? The antennas are apart but can be moved farther. Thanks Chris Kg4bek
Re: [Repeater-Builder] Spectrum Comms SCR200A 220 receiver question
Others experiencing this? The younger hams just don't seem to have the curiosity that I had years ago. 73, Joe, k1ike Except for me!!! And I thank this whole group for making it possible. Ross www.kc7rjk.net
RE: [Repeater-Builder] Re: Coax length, etc. GE Z-Matcher
HOLY CRAP I've been wondering that for some time. Guess the manual isn't always right. and maybe that's why the GE Z-match is there for the recruiting of true GE tuners.. Never-mind keeping your PA happy at 100% DC. I always wanted to ask but never did (for thought of flames from the GE manual) because I thought I heard somewhere that tuning procedure wasn't ideal for most cavity/duplexer applications (on this list in a unrelated post) so investigated. Now I always settled for the best low ratio of the two. PA current/TP1 from z-match. You'll see that the relationship of the two is not even close to linear. What I've found is you basically want to try to be on the edge of both curves knee's.. I think I have the right idea, for a 50mV gain from the TP1 z-match null I could drop PA current by 2500mA. And this was until now (a month ago) that I finally have a good HP8924 SM to help take the guess work out. Plus your PA and TX cavity temps go way down. Just glad to hear I was probably doing the right thing. Also I always did the final 1st 2nd pass cavity tuning this way. Retuning cavities for highest output power with least current vs. low TP1 on z-match. One tuning session on a friends machine with this method dropped TX cavity temps by more then 10deg to almost ambient temp while dropping PA temp, and current by 2 amps with no drop in output power or RX sense. This probably means the match in the cavity coupling or cabling was off but hey that PA will live longer. If I'm wrong or missing something here, let me know. 73's groupies Ross www.kc7rjk.net http://www.kc7rjk.net/ -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of larynl2 Sent: Saturday, August 14, 2010 8:17 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Coax length, etc. GE Z-Matcher --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Jeff DePolo j...@... wrote: c) Although not explictly described in GE's tuning procedures, significant improvement in efficiency can be obtained with proper tuning of the Z-matcher. Tuning for 50+j0 at the input to the Z-matcher is NOT necessarily the RIGHT match! Right, GE's instructions on tuning the Z-Matcher in their base stations are not correct. Instructions should instead describe a procedure that reduces current draw of the amplifier while simultaneously maintaining or increasing the output power. d) To charge more. I'm half-joking on this; I can't say I've statistically seen more or less failures on M2 PA's with or without the Z-matcher, so I'll give this answer half a smiley: .-, If the failures you've seen are in amps with Z-Matchers that were tuned following GE's Z-Matcher instructions, that *could* explain why you've given half a smiley... :-) Laryn K8TVZ
RE: [Repeater-Builder] Coax length, etc.
So will someone post a simple rule of thumb. If you have the option of optimizing cable length from PA to first cavity, IE you haven't made them yet what's the best simple rule of thumb to follow to build them to avoid reactance. 1/2wl if allowed minus coupling loop depth? Or is that past a simple thumb. Also, This will obviously not work well for 220 or 440 or a most vhf repeater setups. So what would the next ideal cable wl be? And so forth. The reason I ask, if your building new cables why not? Answers on here seem to range a lot. Ross kc7rjk
RE: [Repeater-Builder] Coax length, etc.
FORGOT to multiply cable VF then subtract coupling loop depth!!! Forgive me :-) -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Ross Johnson Sent: Saturday, August 14, 2010 11:59 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Coax length, etc. So will someone post a simple rule of thumb. If you have the option of optimizing cable length from PA to first cavity, IE you haven't made them yet what's the best simple rule of thumb to follow to build them to avoid reactance. 1/2wl if allowed minus coupling loop depth? Or is that past a simple thumb. Also, This will obviously not work well for 220 or 440 or a most vhf repeater setups. So what would the next ideal cable wl be? And so forth. The reason I ask, if your building new cables why not? Answers on here seem to range a lot. Ross kc7rjk
Re: [Repeater-Builder] MTR 2000 Help
Are all the original cards in it when it was programmed? If it was programmed with any optional boards installed they must be in place at all times after. Also have you've added any cards after programming that will also cause this fail. Ross kc7rjk From: w5rdw Sent: Tuesday, July 27, 2010 2:57 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] MTR 2000 Help I have a MTR 2000 for the 900 MHz band (hacked to the ham band). It has never been used as a repeater since I acquired it a few years ago, but was scheduled to be on my 927.1125 repeater freq. one of these days. I turned it ON after it had been OFF for a better part of a year (out in the garage but dry). It came on, but instead of the green LED staying lit after it warmed up, the 4 LEDs blinked for sometime and then the red LED (far left) stays lit. The manual says that means a major malfunction. Before I dig into the repeater, does anyone have an idea what has happened? I had just successfully reprogrammed it to a new freq. pair, but this situation has cropped up. Roger W5RDW Murphy, Texas
RE: [Repeater-Builder] Re: Service monitor newbie questions, Determining RX sensitivity with HP 8924C at 12db sinad
Great thank-you for the fast responses. looks like I didn't get deep enough on RB. Web searches are getting harder and harder to find information like that. Looks like I have some reading to do. Thanks again Ross kc7rjk -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of radioman762 Sent: Tuesday, July 27, 2010 8:10 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Service monitor newbie questions, Determining RX sensitivity with HP 8924C at 12db sinad There is also a Yahoo group for these units. Search for hp8924 (without the quotes, of course).
[Repeater-Builder] Service monitor newbie questions, Determining RX sensitivity with HP 8924C at 12db sinad
Hello group, I have been playing with repeaters for quite some time and now I finally own a real piece of test equipment. An HP 8924c, before almost dumping more money into one more, one function, piece of equipment, a spectrum analyzer, I found these 8924c's on eBay... Shopped for about 6 months and found a 100W version for less then a K so I'm very pleased. The manual for this unit is not designed to walk you through any of the analog test procedures or setup. I've figured some of the simple stuff out. Duplex tests, spectrum analyzer/tracking gen ect. and I love this thing so far. Right now before I start dabbling with my first full on GE Mastr RX alignments I'd like to make some sensitivity tests (the right way). There's a lot of bells and whistles on this HP and I think there's some built in sinad measurement tools. I also would like to know how to make the old standard 20db reff test as well as the 12db sinad. Is there any information I missed about using this 8924c's for it's analog functions, setup and test procedures??? Also I plan on building a sampler slug for my bird43 other then that what else is really needed in the tool box for this unit. I plan on using it for TX/RX alignments, band-pass, notch filter adjustments, duplexer isolation, antenna and feed line analysis. Sorry for this very noob of a question but elmers around here with any knowledge of this unit just don't exist. And my friend with an ifr1200 tried to get me started on the sinad testing but I think there is an easier procedure for this HP 8924.c. Thanks for your time RB's Regards Ross kc7rjk www.kc7rjk.net
RE: [Repeater-Builder] Recommendations for a Voter Link
I'm in the exact same boat working on a remote receiver. I don't want the link keyed 24-7 either. I now there are some voters out there that don't require 1950hz and some that don't need it present 100% of the time to keep that voter port active. But are there any other voters in the used or DIY market that's in the HAM budget. That do not require the 1950hz tone at all. Here one I found on RB but I will need eventually 3 ports. http://www.repeater-builder.com/rbtip/wb2whc.html Can one more port be added and has anyone had good success with this unit? Thanks All, Ross kc7rjk -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim - WD6AWP Sent: Sunday, July 25, 2010 3:19 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Recommendations for a Voter Link I'm going to start working on building a link for a remote receiver. I already have a voter and I'll be using a VHF Micor receiver strip for the remote. A couple of mobiles that tune down to 420 might be good as I don't have a lot room. I'm thinking the link transmitter will be keyed 7x24 with tone signaling. However the duty cycle requirement is a problem for mobiles. A microwave system might be possible if I knew what and where to get. Wireline is probably out. I'd like to hear your ideas on how to put this together. Thanks, Tim P.S. Sorry if this post is a dup. The first one did seem to come through this morning.
RE: [Repeater-Builder] Re: Invar Rods
You might save on Invar if you can get away with using coupling nuts to reuse your short rods, and don't forget the jam nuts. I've done it with no measurable degradation. Ross Kc7rjk -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of burkleoj Sent: Friday, July 16, 2010 11:57 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Invar Rods Glenn, I need 6 of them for a Sinclair duplexer that I have. Someone cut the rods off when it was originally on a commercial frequency. The rods in my duplexer are so short that it will not tune below 147 MHz before they disappear inside the top of the cavity. I can get some dimensions for you to see if the ones you have may work. Thanks, Joe - WA7JAW --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Glenn Little WB4UIV glennmaill...@... wrote: Does anyone need INVAR rods? I salvaged some from a TV audio / video RF combiner. 73 Glenn WB4UIV
RE: [Repeater-Builder] Transmitter Combiner
You could try a duplexer? There's enough channel separation it should work OK. Not sure what duplexer would be best for running duplex though each side but I'm sure there out there. 73 Ross kc7rjk -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of na4it Sent: Thursday, July 15, 2010 1:04 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Transmitter Combiner Is there a cheap way to combine two txcvrs into one antenna... 144.39 APRS and 145.550 packet?
RE: [Repeater-Builder] Repeater Control Operator via Other-Than-Phone-Line
Yet another option. 930Mhz serial data radios. I found a pair Data Link Group radios on eBay for $100. Would be like plugging it in to the back of your computer. There quite easy to get running. Well over 20miles LOS. And one of my radios was on an omni. I use them for weather stations and camera control. Have fun 73 Ross www.kc7rjk.net http://www.kc7rjk.net/ -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Mike Besemer (WM4B) Sent: Thursday, July 08, 2010 7:32 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Repeater Control Operator via Other-Than-Phone-Line At our club meeting tonight a discussion came up regarding the cost of the phone line to our 2-meter repeater system. Originally it was there for the Autopatch, but has evolved to being primarily used for me to program the controller (CAT-1000) and to control the system. (The autopatch is rarely used, since everyone carries a cellphone now.) Everyone understands that the phone line is needed for control and programming, but we started toying with other ideas. Specifically, having an Internet connection at the site seemed like it had a lot of potential, but frankly I don't know why! It'd be nice to run an I-Gate from that location (we already have an APRS weather node there), but it's not essential. I could probably use it to monitor the site as well, but that's not really much of a concern either. So, the question is, how can we use Internet to control/program the CAT-1000? We could get Internet at the site for about the same cost as the phone, and if we could use it for repeater control/programming AND the other things I mentioned, it'd be a better deal. Can IRLP be used for control/programming? I'm not familiar with that system whatsoever, but am always willing to learn. 73, Mike WM4B
RE: [Repeater-Builder] kyodo kg108 uhf
You know that com port works? Older machines serial ports were poorly or not even buffered sometimes. Also if this is a programming laptop, where you use it to program other radios, make sure none of the other programming software is tying up that com port while the machine is running. Ross kc7rjk -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kerincom Sent: Friday, June 11, 2010 7:49 AM To: mail=repeater-buil...@yahoogroups.com Subject: Re: [Repeater-Builder] kyodo kg108 uhf Already done that Thank You, Ian Wells, Kerinvale Comaudio, 3A Murchison Street,Biloela.4715 Ph 0749922449 or 0409159932 or 0749922574 www.kerinvalecomaud http://www.kerinvalecomaudio.com.au/ io.com.au ---Original Message--- From: wd8chl mailto:wd8...@gmail.com Date: 06/11/10 23:30:03 To: Repeater-Builder@ mailto:Repeater-Builder@yahoogroups.com yahoogroups.com Subject: Re: [Repeater-Builder] kyodo kg108 uhf On 6/11/2010 7:45 AM, kerincom wrote: Hi guys .I have the genuine software and programming cable and kg108 uhf radios and I am trying to read and program them .The software is installed on a Toshiba 700mhnz laptop running win98se .and when I try to communicate with the radio it comes up with error in communications .I have tried running it in dos and still the same .It seems to be a com error because I have 2 programming cables and the get the same result with both.Can anyone suggest anything I'm not familiar with those, but chances are if they are more than 6-8 years old, the software is DOS, and Windows won't allow control of the RS-232 port the way it wants. Hit the 'Start' button, and in the shutdown menu, one selection will be Restart in MS-DOS mode. Select that, and it will take you to a true DOS environment. You'll have to navigate back to the directory you have your program in from there using DOS commands. Jim
RE: [Repeater-Builder] Re: Antenna separation question
I also used a 3db collinear as a TX at the same height as the 4 bay dipole, and noticed quite a bit more isolation just from that antenna. I believe the folded dipoles radiation pattern allows for many more vertical spikes, So you should be in great shape with those station masters and said filtering. In your second question, yes. I was thinking about going down that same road for RX only. If both your receivers have pass cans you may try this. From your dual band RX antenna feedline run a T to you uhf and vhf cavities. Use a UHF ¼ wavelength + velocity factor and coupling loop depth, jumper to connect you VHF pass cavity. Then calculate the save VHF length for the UHF cavity I havent done this yet so let me know how it goes. HiHi Ross kc7rjk -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kc0mlt Sent: Wednesday, June 02, 2010 10:12 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antenna separation question Thansk for the input. That is almost exactly what I'm going to put on the air as far as cans go. I'll have a Hamtronics exciter and receiver amped up by a 110 Watt Micor base amplifier. Just about the same heights too. Antennas are both staion masters. but I like knowing that what I have been thinking about will actually work. One other question someone may know. Is it possible to run say a VHF and a UHF repeater off a dual band antenna with a diplexer or is there going to be issues. Thanks Wade KC0MLT --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Ross Johnson kc7...@... wrote: That's exactly what I'm doing. VHF GE mastrII at 100 watts goes through 2 8 Sinclair pass cavities set at .5db gives 80 watts to the antenna. 4 bay exposed dipole at 75' The receiver and preamp goes through only one 8 Wacom also set at .5db then up to the collinear receive antenna at 100' Very very little desense almost undetectable. Also with the pass cavity on the receiver side preamps seem to be much more usable and effective in the real world. This machine hears very very well! More can be seen from my website. www.kc7rjk.net http://www.kc7rjk.net/ ~Ross -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com ] On Behalf Of kc0mlt Sent: Tuesday, June 01, 2010 10:28 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] Antenna separation question Ok just kicking this idea around the other day and the question came up about antenna separation. I know the basic 2 meter antenna separation is 50ft. (I am thinking 60ft to be safe) But is it possible to get them closer if I place some cavities on either the receive or transmit sides. Sounds dumb from some certian points of view, but I am waiting on the arrival of a decent duplexer (could be some time out though)so in the mean time I would like to get this up and going with a split antenna system for now. I was thinking maybe a 30ft separation... Would this idea work? If so does it need to be modified from what I was thinking?
RE: [Repeater-Builder] Antenna Separation UHF Low Power
There's should be more in your question. Are they going to be tower mounted where they will be directly above and below the other. That's very important. If so I'd say at least 70'-100' of vertical separation but if your not running hardline with no filtering whatsoever you will still likely have problems with desense just through the coax feedlines. If the separation isn't exactly vertical say on two towers on a site. Even with one antenna at 50' and the other is at 200' the towers would need to be hundreds, maybe thousands of feet separation. A pair of simple pass cans could give you what you need for isolation. No UHF Moto cube cans lying around??? Also you can try more of a split just for testing. 435rx 449tx say. Ross kc7rjk -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Steve Sent: Wednesday, June 02, 2010 2:30 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Antenna Separation UHF Low Power I am looking at putting together a 5w uhf repeater using 2 uhf m200s and a Rick we have on hand. We want to do coverage tests prior to investing in a duplexer, how far apart do we need to place our antennas?
RE: [Repeater-Builder] Heavy Duty Antenna question....
You still have those photos? I wouldn't mind looking into building my own. kc7rjk Ross -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Mike Morris Sent: Monday, May 31, 2010 7:43 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Heavy Duty Antenna question At 10:07 AM 05/31/10, you wrote: well, i tried to search, but.. alas, sorting thru 1400+ posts just isn't going to work. i need actual use facts on high altitude (11k feet), severe duty antenna selection... i've always been a stationmaster (fiberglass) antenna guy - and never had a problem... but...i've never put an antenna up at this height. i am going to need something good for 150+ MPH winds, ICE, etc. Open to ideas. One word: Scala. They are in Medford, Oregon. Phone 541-779-6500 Email is communications at kathrein dot com Kathrein-Werke KG of Germany bought them but everyone I know of still calls them Scala. The Cal Tech Seismo Lab has a bunch of radio linked seismographs and one is on Mt Whitney at 14,500 feet. Another is on Mount San Antonio (also known as Mt Baldy) at over 10,000 feet. Those plus a lot more seismographs at lower altitudes all use Scala beams. Now those are beams but I've seen Scala Omni antennas as well. They are TOUGH. In short, Scala make antennas that survive, but they are not cheap. http://www.kathrein-scala.com/ main web site http://www.kathrein-scala.com/vhf-high.htm VHF High Band http://www.kathrein-scala.com/uhf-mobile.htm UHF Despite the words uhf mobile they make UHF station antennas as well. I'd get their catalog, as well as the ones from Sinclair and Telewave and maybe even Bogner. Just be sitting down when you get to pricing out your new toy. Years ago a friend could not afford the Scala he wanted, so he took lots of photos of one that was already in place at a different site. Those photos were blown up to 8x10s (I had access to an enlarger and a darkroom then) and he took them over to his brother-in-law the welder. A couple of weeks later he had a homebrew copy of a Scala VHF Omni with a reflector (think 8 foot tall corner reflector) A trip to the galvanizers and then to the mountaintop resulted in a very LOUD system Mike WA6ILQ
RE: [Repeater-Builder] Antenna separation question
That's exactly what I'm doing. VHF GE mastrII at 100 watts goes through 2 8 Sinclair pass cavities set at .5db gives 80 watts to the antenna. 4 bay exposed dipole at 75' The receiver and preamp goes through only one 8 Wacom also set at .5db then up to the collinear receive antenna at 100' Very very little desense almost undetectable. Also with the pass cavity on the receiver side preamps seem to be much more usable and effective in the real world. This machine hears very very well! More can be seen from my website. www.kc7rjk.net http://www.kc7rjk.net/ ~Ross -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kc0mlt Sent: Tuesday, June 01, 2010 10:28 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Antenna separation question Ok just kicking this idea around the other day and the question came up about antenna separation. I know the basic 2 meter antenna separation is 50ft. (I am thinking 60ft to be safe) But is it possible to get them closer if I place some cavities on either the receive or transmit sides. Sounds dumb from some certian points of view, but I am waiting on the arrival of a decent duplexer (could be some time out though)so in the mean time I would like to get this up and going with a split antenna system for now. I was thinking maybe a 30ft separation... Would this idea work? If so does it need to be modified from what I was thinking?
RE: [Repeater-Builder] Fwd: DB4379UHF combiner
You might try finding a spec for a similar maybe same model 2ch combiner. Then see if your isolator cabling system is the same. Ross -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Ted Leonard Sent: Thursday, May 27, 2010 11:33 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Fwd: DB4379UHF combiner To the group, I received the attached e-mail from a friend in the two way business. Does anyone know if his goal can be met as he describes below? Also could someone point me to the tuning instructions for this beast. Thank you, Ted W3VG Original Message Subject: DB4379UHF combiner Date: Thu, 20 May 2010 11:16:13 -0400 From: Robert Harvey mailto:freedom...@windstream.net freedom...@windstream.net To: Ted Leonard mailto:n2...@verizon.net n2...@verizon.net Ted, you're the filter guy. I have a DB products DB4379-4404B 4 channel UHF combiner. You did a little bit of tuning on it once in the shop. Do you know, or can you find out, if it can be turned into two, 2 channel combiners? I want to combine 461.625, 461.650, 463.625 463.650 but the combiner is speced at 50KHz spacing. There are two splits of only 25KHz on the frequencies I need to work with. Combining 461.625 and 463.625 on one combiner and antenna and combine 461.650 and 463.650 on another combiner and antenna would save me antennas and feedline and lots of money if I can modify the combiner I own. Bob Robert D. Harvey Freedom Communications, Inc aka: RDH / TransCom voice (716) 664-2659 fax (716) 483-5968 email freedom...@windstre mailto:freedom...@windstream.net am.net
RE: [Repeater-Builder] What did I steal off eBay. Unknown wacom bandpass
That’s great. Just what I wanted to hear J Thank you for the info. 73’s Ross KC7RJK -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Steven M Hodell Sent: Thursday, April 15, 2010 5:27 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] What did I steal off eBay. Unknown wacom bandpass I have several of these cavities, they are Wacom VHF Band Pass filters, and they should tune fine in the 144-148 MHz range. - Original Message - From: Ross Johnson Mobile mailto:kc7...@comcast.net To: repeater-builder@ mailto:repeater-builder@yahoogroups.com yahoogroups.com Sent: Wednesday, April 14, 2010 10:42 PM Subject: [Repeater-Builder] What did I steal off eBay. Unknown wacom bandpass I got a real good deal on this unit. Uhf or VHF I can use it. I think its VHF but maybe someone can shed light. It has no markings at all... 25 high 8 across, coupling loop 1.5 long .75 wide. Any ideas. Pic attached
RE: [Repeater-Builder] What did I steal off eBay. Unknown wacom bandpass
No service monitor or na to sweep it here. It's a wacom unless they could be re-naming. It's the same exact construction of that 8 uhf wacom in the background. Thanks all Ross kc7rjk http://www.kc7rjk.net Eric Lemmon wb6...@verizon.net wrote: The sticker next to each coupling assembly looks like those on Telewave cavities. The size of the can suggests it is VHF High Band. Did you measure its pass frequency before opening it up? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Ross Johnson Mobile Sent: Wednesday, April 14, 2010 7:43 PM To: repeater-builder@yahoogroups.com Subject: [Repeater-Builder] What did I steal off eBay. Unknown wacom bandpass I got a real good deal on this unit. Uhf or VHF I can use it. I think its VHF but maybe someone can shed light. It has no markings at all... 25 high 8 across, coupling loop 1.5 long .75 wide. Any ideas. Pic attached
[Repeater-Builder] Dual receivers on one antenna for RX only site
Hello to the group, My name is Ross KC7RJK This is my first post. Most questions are answered from that amazing and up to date web site! I thank you all involved very very much for that. Well here's the question I've found little and conflicting info on the web about. So feel free to point me the right way here. Can a dualband antenna VHF/UHF for RX ONLY be fed to two receivers one VHF, one UHF, without a quote duplexer using a T instead? Here's the idea. This is a remote RX site. The idea is to run something like a beefed up X500 dualbander at tower top, then 7/8 hardline 100 feet down to the receivers. Both receivers will have one or two bandpass cavities inline before the T. Would a duplexer be necessary in this case. Or could it be done with proper cable lengths and a T? Thanks for your time and for the probably obvious answer I'm not sure of. Regards Ross KC7RJK
RE: [Repeater-Builder] Re: Dual receivers on one antenna for RX only site
Thanks for the replys everyone. That cleared it up for sure. I will go ahead and build the T to cavity cables to one electrical wave length for the other band. And is that ¼ wave plus velocity factor of cable? Which will be FSJ1. Here is some more detail on the system. It will go in stages. The final stage will be this remote receive setup with a UHF link on the bottom of the tower to the transmitter site. Also toying with a VOIP link with UHF as a failsafe. At this point the receivers are on separate antennas at the top of the tower, with 2 bandpass Sinclair 1-150-1S7 cavitys on the VHF, and one big Wacom cavity on the UHF receiver. The remote TX site hasnt been installed yet (waiting to find a MSR2000 UHF RX board for this divorced VHF TX site) so the transmitter is temporally at this site also. There are two bandpass cavitys DB4001s on this Mastr II transmitter with the antenna 40-50 feet down from the receive antenna. Sensitivity is shocking good right now with this setup. Very little RX loss, and very little desens. Will the receivers stay on one frequency as in a repeater receiver or do you need to move around each band a bit? Yes they will stay put. How much other RF is around? ... Does the site have a lot of transmitters and are any of the high power monsters as in the case of paging or broadcast? None in these bands! :-) But wireless ISP Ive found to be very noisy allover the place there. 50Mhz and up! Thanks again everyone! -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of skipp025 Sent: Tuesday, March 09, 2010 4:29 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Dual receivers on one antenna for RX only site Ross Johnson kc7...@... wrote: Hello to the group, My name is Ross KC7RJK This is my first post. Hi Ross, My name is skipp and I'm a junkoholic... hi skipp and I %#*^ scuse me, lost my mind for a moment. Moving along Most questions are answered from that amazing and up to date web site! I thank you all involved very very much for that. We don't play up the RB web site nearly enough... we also don't let Kevin, Scott or Mike run with scissors. Well here's the question I've found little and conflicting info on the web about. So feel free to point me the right way here. Simple, go west... better weather and less humidity. Can a dualband antenna VHF/UHF for RX ONLY be fed to two receivers one VHF, one UHF, without a quote duplexer using a T instead? Of course, but it may not be the best situation. Here's the idea. This is a remote RX site. The idea is to run something like a beefed up X500 dualbander at tower top, then 7/8 hardline 100 feet down to the receivers. Both receivers will have one or two bandpass cavities inline before the T. Would a duplexer be necessary in this case. Or could it be done with proper cable lengths and a T? Doesn't even need the special cable lengths but there is a reason for doing everything and here comes questions 101. Will the receivers stay on one frequency as in a repeater receiver or do you need to move around each band a bit? How much other RF is around? ... does the site have a lot of transmitters and are any of the high power monsters as in the case of paging or broadcast? If you don't have a lot of adjacent frequency operation going on there are two other options to consider. One is the Diamond or Comet type of band splitter, which actually would take the place of your T and be much better. Model CF-4160K http://www.universa http://www.universal-radio.com/CATALOG/hamantm/cduplex.html l-radio.com/CATALOG/hamantm/cduplex.html And another very nice option would be the DCI dual band filter Model: DCI-146-444-DB. http://www.dci. http://www.dci.ca/?Section=ProductsSubSection=Amateur ca/?Section=ProductsSubSection=Amateur And you can use the plain T, a more traditional signal divider and various combination of band-pass cavity layouts. Thanks for your time and for the probably obvious answer I'm not sure of. Regards Ross KC7RJK be more worried when you feel sure of yourself. cheers, skipp
