Re: [Repeater-Builder] Re: Repeater receiver testing
Hi yes sort of, getting a bit confused my end. What I usualy do is using a sig gen on the tx port put in the tx freq, terminate the ant port at 50 ohms put my analyser on the rx port and see what level of tx freq iam getting ie -80,-90 or whatever. Steve - Original Message - From: Tim tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Monday, July 26, 2010 12:06 AM Subject: Re: [Repeater-Builder] Re: Repeater receiver testing Hi Steve, I measured each way to the common point... RX to antenna Tx to antenna, and each one had a notch of about 102dB at the opposite frequency. With the 50 watts at the antenna port is where I see the -55dBm on the receiver port. (into the spectrum analyzer). Are these the measurements you mean? (you are up late tonite!) tim Yahoo! Groups Links
Re: [Repeater-Builder] Anybody have a clue ?
Thanks for all the info. Now I know what to put on the Test Equipment page for that wattmeter. Mike
RE: [Repeater-Builder] Recommendations for a Voter Link
The idle marker tone system was designed for wirelines and adapted to microwave shots. 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. Have a SPDT reed relay driven by the link receiver RUS (or COR). Links can be on 420Mhz, 438-439Mhz, 900Mhz, or 1200 Mhz. 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. 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. The GE voter performance has the Doug Hall beat hands down. 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 At 07:34 PM 07/25/10, you wrote: 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.htmlhttp://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.
[Repeater-Builder] Open Rack
All-- I have a nice 6' open rack here that I would like to give away--- South San Francisco bay area a bit North of San Jose--- Scott, N6NXI
RE: [Repeater-Builder] Re: Out Door Radio Cabinet
Hi, Larry,
I'm sorry, but I gave last one way last week.
Gregory
-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Larry Watkinson
Sent: Sunday, July 25, 2010 9:58 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Out Door Radio Cabinet
sorry it has taken so long for me to get back with you. Can you tell me
about the cabinets you have available., size, do they have rack mounts,
etc.
I actually may be able to get someone to stop in CA a help me get one or
I
may be able to get someone to drive me down.
Larry
-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 ac6vj
Sent: Monday, June 28, 2010 9:41 AM
To: Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com
Subject: [Repeater-Builder] Re: Out Door Radio Cabinet
Hi Larry,
I have a stash of traffic signal boxes here in Northern California.
I donate them free of charge to any good Ham cause.
AC6VJ {ac...@cds1.net mailto:%7Bac6vj%40cds1.net }
--- In Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com , Larry Watkinson
lwatkin...@...
wrote:
I am looking for a outdoor radio cabinet, something like a traffic
control box.
I am in Olympia and would be able to go within 100 miles of Olympia,
WA. I could pay shipping to Olympia if outside of 100 miles.
Larry KC7CKO
Yahoo! Groups Links
No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.439 / Virus Database: 271.1.1/2967 - Release Date: 06/28/10
06:37:00
Re: Re: [Repeater-Builder] Recommendations for a Voter Link
If you have a GE VOTER use the COS from the Receiver to key a relay that will apply the E/M voltages to the Voter. remote transmitter down, no voter action. remote transmitter up Voter working. We used the tone for microwave hops and telephone lines. David Jul 26, 2010 03:37:47 AM, Repeater-Builder@yahoogroups.com wrote: On Sun, 25 Jul 2010 19:34:58 -0700 Ross Johnson kc7...@comcast.net wrote: 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? What about a Doug Hall voter? http://www.dheco.com/voter.htm
RE: [Repeater-Builder] Re: Repeater receiver testing
Good thoughts Milt, and I'll add a few While not an easy thing to find I would suggest that you most likely need some sort of a bandpass cavity on the receiver to protect from the noise that gets past the heliax notches. Remember that a notch duplexer only removes the notched portion of the TX signal on the RX side and the RX signal on the TX side, all other noise is passed directly to the load. Thus you only have two small notches, one at the RX frequency and one at the TX frequency. Everything else is passed. A duplexer specification that often goes overlooked is mid-band isolation; that is, how much isolation there is between Tx and Rx ports mid-way between the Tx and Rx frequencies. For notch-only duplexers, this value is often very low, often less than 10 dB. The effect of low mid-band isolation is that wideband noise or spurs from the transmitter can result in receiver desense, even if there is enough isolation at the operating frequencies. In other words, the wideband noise passes right across the duplexer at frequencies far enough removed from the notches to cause problems. For pass/reject or bandpass duplexers, the mid-band isolation will be substantially higher, may be somewhere in the range of 30 to 60 dB depending on band, offset, number of cavities, etc. Mid-band isolation is often quoted in manufacturer's specs as a simple scalar value, if it's given at all. Quite often they just give you isolation, and that's just at the Tx and Rx frequencies proper; it doesn't tell you anything about what's happening at other frequencies. A swept transmission response across a broad range from Tx to Rx port with the antenna port terminated will show the true isolation you're getting. As far as adding a pass cavity to attenuate desense caused by noise or spurs coming from the transmitter, it would most likely be more effective if you put it on the transmitter leg of the duplexer rather than the receiver leg. You probably should also look at the TX signal to check for spurs. Micors are generally pretty clean machines, but keep in mind that lowband repeaters were fairly rare back in the day; I don't know if duplex isolation curves were ever published for lowband Micors (ZZU, you QRV?). For the Mastr II you only needed about 50 dB of carrier supression and a little over 60 dB of noise supression for 100 watts at 1 MHz split. I also have had duplexers that look good with a tracking generator but fail under TX power. And we've all had antenna systems that did the same. And I've had dummy loads that did the same as well; point being, don't rule out a problem in your test equipment... --- Jeff WN3A
[Repeater-Builder] GE Mastr II stuff in California
FYI GSA is selling some Mastr II stuff in Placerville, CA. Eldorado National Forest. I can send a link to anyone who is interested.
Re: [Repeater-Builder] Re: Repeater receiver testing
At 7/25/2010 15:54, you wrote: Hi Jeff yes I know -55db is I think around 399 microvolts which will flatten any receiver, I sure hope not; there are many signals coming down my antenna that are that strong. In fact, my 440 repeater 13 miles away is at about that level at my antenna connector. Bob NO6B
Re: [Repeater-Builder] Antenna Advise
my advice for what its worth is to use commerical grade antennas such as DB224 (VHF) AND DB 420 (UHF) or the Sinclair equalent. No other part of a repeater system can affect both the rx and tx as much as a GOOD/BAD antenna. As to the power levels, remember that the mobiles must be heard by the repeater as well as hearing the repeater for it all to work. So the mobiles are also going to have to run simular power level to the repeaters. I suggest turning the amps down to 50 - 75 watts out of the filters and see if that doesn't come close to matching the ranges. 73's and good luck Jeff N5sxq w6ghz ryo...@sonic.net wrote: Hello Group, Thank you for being here and reading this. I am new to this group and need antenna advise for a repeater system I am attempting to build. My electronics skills are very limited, but I know enough to assemble a system and get it on the air. This system consists of two repeaters linked by one controller in the same enclosure: 1) Motorola Micor vhf w/140W amp 2) GE Master Exec II uhf w/250W amp If one asks why I'm considering this much power, the reasons are: 1) The amps are available. 2) The terrain this system will be operating in is hilly with a lot of trees and vegetation. 3) The system is not on a hill top. 4) The antenna(s)for this system will only be on a 100' alum tower. 5) Several users are out in a fringe area. I am aware a good antenna can trump an amp and I'm open to alternate solutions. I have enough hardline and connectors to make a few runs up the tower if needed. Is there a practical, cost effective solution to antenna both of these repeaters? How do I go about acquiring the solution? Money is an object and one that is becoming less available as this project moves forward. Any thoughts are much appreciated. Thank you, Richard Young W6GHZ Shelby, NC.
[Repeater-Builder] Re: Repeater receiver testing
Hi Jeff, Thanks for the info. any idea about the complexity of the 'summing' device? Can I do with a resistor combo, then perhaps sub some from the actual generators' output? Tim --- In Repeater-Builder@yahoogroups.com, Jeff DePolo j...@... wrote: The holy grail for FM performance testing, which includes adjacent channel rejection measurements, is EIA/TIA-603. I believe revision C is the latest. Unfortunately, you'll have to pay to get a copy of that document unless you can scrounge one up. To summarize how the test is done (and I'm doing this from memory, so someone please verify/correct me). 1. You need a way to sum the output of the two sig gens together such that they are properly isolated from each other, and done in such a way that the amplitudes can be calculated accurately at the output of the summing device. 2. You start out by measuring the 12 dB SINAD of the receiver with only the on-channel signal generator active (standard SINAD test, 3 kHz deviation, 1 kHz tone, typically measured at the speaker terminals after deemphasis/filtering/etc.). Simple enough. 3. Increase the RF level of the on-channel generator 3 dB higher than the 12 dB SINAD sensitivity value you found in step 2. This will push the measured SINAD up higher than 12 dB obviously, that's what's supposed to happen. 4. While still generating the on-channel signal, now also generate a signal on the adjacent channel, modulated by a 400 Hz tone at 3 kHz deviation. 5. Increase the level of the adjacent-channel signal until you degrade the SINAD reading of the on-channel signal back down to 12 dB (remember, it was something greater than 12 dB, because you had increased the RF level by +3 dB before you started introducing adjacent-channel dinterference). 6. The difference (in dB) between the offending signal and the 12 dB SINAD sensitivity measured in step 2 is the adjacent channel rejection ratio. So, for example, if the 12 dB SINAD sensitivity was measured at -117 dBm in step 2 without any interference, and you were back down to 12 dB SINAD in step 5 when you had the interfering signal cranked up to -30 dBm, the adjacent channel selectivity would be 87 dB. --- Jeff WN3A -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of tahrens301 Sent: Saturday, July 24, 2010 10:27 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Repeater receiver testing I have this lowband Micor receiver that I want to test for adjacent channel rejection. I have two calibrated signal generators and a calibrated spectrum analyzer if I need it. How can i measure the rejection of the off channel signal? Thanks, Tim
[Repeater-Builder] Re: Motorola R-2200A User Manual
Sorry if you get a double post on this. The first one that was sent out didn't go through on my end. I have R2200A Maintenance Manual 6991069A76. Did they make a generic users manual? There are a lot of stuff on here I am not familiar with. Thanks, Robert KD4YDC --- In Repeater-Builder@yahoogroups.com, Eric Lemmon wb6...@... wrote: Robert, I have good news and bad news. The bad news is that the R2200-series Operator's Manual 6881069A79 is out of print and is NLA. The good news is that the R2200A Maintenance Manual 6991069A76 is still available from Motorola Parts, for about $58. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Robert Sent: Sunday, July 25, 2010 5:25 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Motorola R-2200A User Manual Does anyone have a link to this? Would love it if this was in pdf as well ;-) 73, Robert KD4YDC
[Repeater-Builder] Re: Recommendations for a Voter Link
We have used the LDG RVS-8 voter with great success. http://www.ldgelectronics.com/c/252/products/5/19/1 It is an 8 channel voter and does not need a 1950hz tone to operate, and is within a ham's limited budget. In fact it works so well, one was installed for a local sheriff's office. They have 4 remote sites plus the main site. Not a single hick-up with the system in over 3 years, and it provides 100% handheld coverage for the deputies on VHF. As far as links go, there is a number of ways to do them. But to get you started, visit this link, lots of good info to get you going: http://www.repeater-builder.com/rbtip/remotereceivers.html In short, use flat audio for your links (no pre or de-emphasis), use the same type equipment whenever possible, and keep the hang times short. A good sounding remote link should sound the same, or as close as possible, to the main input. Makes the voting process smoother, and adjustments easier. Good luck! Steve KD8BIW Repeater Tech KD8BIW/R 224.580 N8IHI/R 147.105 W3YXS/R 146.745 KD8JBF/R 443.325 http://www.kd8biw.com http://www.duplexcom.net
[Repeater-Builder] Re: Recommendations for a Voter Link
Hmm... My first post didn't make it through... Anyway.. We use, with great success, the LDG RVS-8 voter. It is an 8 channel voter, does not need a 1950hz tone to function, and is within the average ham's budget: http://www.ldgelectronics.com/c/252/products/5/19/1 It works so well in fact, that one was installed on a local sheriff's repeater. They have 4 remote receivers plus the main site on a VHF repeater. It has been working flawlessly for 3 years, and gives the deputies 100% handheld coverage of the county... As far as the links goes, there are a number of ways to do them. To get you started, read this first. Lots of good info here: http://www.repeater-builder.com/rbtip/remotereceivers.html In short, use flat audio on the links (no pre or de-emphasis), use the same equipment whenever possible, and keep the hang times short. A remote link should sound the same, or close to, the main input. This makes adjusting the voeter easier, and gives you smooth voter operation. You should not be able to tell when the voter switches by the sound of the audio (within reason). Good luck! Steve KD8BIW http://www.kd8biw.com Repeater Tech KD8BIW/R 224.580 N8IHI/R 147.105 W3YXS/R 146.745 KD8JBF/R 443.325 It is often easier to ask for forgiveness than to ask for permission. -- Rear Admiral Grace Murray Hopper, USN
[Repeater-Builder] Re: Icom OPC-617 Cable
I soldered the f and D bead and sill wont work,got the PTT to work but i still cant get any audio to transmit or recieve through the OPC-617 cable, i even took the mic out if my david clark head set connected it straight to the pin 4 and 8 and it still wont transmit my voice. --- In Repeater-Builder@yahoogroups.com, Duane Hall du...@... wrote: You would want Rx audio from 2 and 7, Tx audio in on 4 and 8, solder bead D in the radio. I dont recall if there is a VOX option in the radio. If the intercom is full duplex, how will you key up the radio (PTT)? DB9 1Dimmer in 2De-Emph Audio Out (affected by Vol Pot) 3Discriminators Audio (Un Squelched) 4Tx Mod In 5PTT in 6COR out (probably need a pull up resistor) 7Ground 8Ground 9Ground Pin 2 - You can set a minimum level via Set Mode Pin 4 - Tx freq response. Solder bead F for data, solder bead D for audio Pin 5 - Enable external PTT via software. CommonExpertEPTT Pin 6 - Enable COR via software. Disable the 2/5 tone function for the selected channel. CommonExpert RX EXO to ON, and delay timer to OFF Pinout info on page 16 at http://www.repeater-builder.com/icom/pdfs/icom-ic-f111-f121-f211-f221.pdf Duane AB8QU On 7/13/2010 10:28 PM, ryan_151 wrote: im trying to use the OPC-617 cable with an Icom f121 radio to connect it to an intercom and need to know how what pins to use to connect my mic+- audio into the F121 radio and the f121 radio audio out +-. Any help with this woud be great, Thanks
[Repeater-Builder] Re: Recommendations for a Voter Link
Tim, I am not sure or do not remember what you have for a voter, but I have used the Doug Hall voters in a COR mode with very good results. I know there are some pretty good articles on adapting the Motorola Micor series of voters from tone to COR. This is one of the projects on my to-do list. Have all of the necessary parts, just need some time. Microwave or something keyed up 24-7 as you mentioned is the best, but don't discount using the COR method as it does work very well. The best results will be obtained using radios from the same series throughout the system. This will make it much easier to balance and equalize the audio response curve and levels. The Doug Hall voter does require discriminator audio from the receivers. We have used the Doug Hall voters with both Arcom RC-210 and Link-Comm RLC-1 external controllers with very good results. Good Luck, Joe - WA7JAW --- In Repeater-Builder@yahoogroups.com, Tim - WD6AWP tisaw...@... wrote: 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: Repeater receiver testing
yes I know -55db is I think around 399 microvolts which will flatten any receiver, I sure hope not; there are many signals coming down my antenna that are that strong. In fact, my 440 repeater 13 miles away is at about that level at my antenna connector. Reminds me of a test I did with a GE MASTR Pro VHF receiver (stock - no preamp - ER-41C) and a GE MASTR II PLL exciter (stock - 200 mW output) and a tee connector. Receiver and exciter on each end of the tee (with short cables) and antenna/service monitor on the center. As I remember, the frequencies were about 6 MHz apart and the 'repeater' would duplex reasonably well considering no filtering was used between the units. Of course, I'm not saying there wasn't desense, but it worked - pretty well. Obviously, the 200 mW was split into two paths and who knows how much was hitting the input port of the receiver, but lets say half of it was - 100 mW. That power level is +20 dBm. I can almost guarantee you that transmitter side band noise is what created the desense - not the shear power of the transmitter. +20 dBm is 2,240,000 ?V or 2.24 volts of RF. My receive antenna for the UHF remote receivers is top mounted across the tower face beside the VHF stick. The VHF repeater runs 250 watts. 4 watts of VHF power appears at the splitter (in the shelter - including feedline loss) which feeds the 4 UHF receivers. The splitter (old CATV type) gets warm - you figure out how much VHF power is getting to each UHF receiver grin. Kevin Custer
[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
