[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
Re: [Repeater-Builder] OT: Licensing Exam Info
Hi Ralph, Two things. 1. You are correct. A good memory is a plus. I went one step further and created a UNIX shell script to use the entire database of questions and test myself over a period of months on answers wrong vs time to take the entire test for each class of license. When I got 100% everytime, I would continue with the next class testing. When it came time for the VE session, I would take the test for the 100% class and then take the next class. Since the VE's would not tell me if I had any questions wrong (they just tell you PASS or FAIL), I don't know how well I did. I passed the Technician test and took the general, which I was not ready for and FAILED. The next VE session I took the general and passed it. Knowing that I was averaging about 60% for the Amateur Extra test, I still took it and actually PASSED. I know most of the stuff off the top of my head. For some of the harder stuff, I know where I can find it (the internet). OBTW, the question pool can be located off of the arrl.org web site at http://www.arrl.org/question-pools As for where you can find a VE session, arrl.org has a session finder at http://www.arrl.org/find-an-amateur-radio-license-exam-session 2. Part 95 is not the Amateur part. It is Part 97. FCC Part 95 is for Personal Radio Services (GMRS, FRS, Radio Control Radio Services, Citizens Band, etc.) http://www.gpo.gov/fdsys/pkg/CFR-2009-title47-vol5/pdf/CFR-2009-title47-vol5-part95.pdf FCC Part 97 is for Amateur Radio Services. http://www.gpo.gov/fdsys/pkg/CFR-2009-title47-vol5/pdf/CFR-2009-title47-vol5-part97.pdf The above links are from the FCC web site. http://wireless.fcc.gov/index.htm?job=rules_and_regulations Chuck From: Ralph Mowery ku...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Fri, July 23, 2010 4:28:27 PM Subject: Re: [Repeater-Builder] OT: Licensing Exam Info How much do you know about electronics and radio in general ? If to some extent , the exam is no problem. Even less if you have a good memory. There are 3 classes now. The Technician, General. and Extra. For each one there is a pool of about 300 questions and answers . That is the exect questions and answers for the test. To take the test you have to go to where there are 3 or more qulaified examiners. Some ham clubs give the test every so often and many times at hamfests (flea markets for hams). Each class requires about 30 to 50 questions to be answered. they are all multichoice. I think it is 70% for a passing grade. When applying for the test , apply for all 3 classes.. It is usually all the same price. If you pass the first one, you can take the next higher test. There is no code (CW) test now. Somewhere around $ 15 for the test now. After you are licened , it is good for 10 years and does not cost anything to renew it. That $ 80 is way too much. You can buy books with the questions and answers or download them from places on the internet. Go to www.qrz.com and look for the prictce test. Give it a try and see how well you do. I have been a ham for over 35 years and can usually hit about 90% on the practice test on QRZ.com in about 10 minuits for each of the 3 tests. I do that from time to time when I hear how hard some say the test is. If you want to learn something about ham radio, go to arrl.org and get one of the handbooks. Think they are around $ 50 now. You can go to e-bay and get some that are a few years old for only a few dollars. Also at arrl.org look at the amateur rules. Part 95 of the FCC rules. Ham radio rules usually differ from comercial rules in that mostly the ham rules state what you can not do instead of what you can do for many parts. If you have your comercial license, the test is similar and should be no problem. From: La Rue Communications laruec...@gmail. com To: Repeater-Builder@ yahoogroups. com Sent: Fri, July 23, 2010 12:43:34 PM Subject: [Repeater-Builder] OT: Licensing Exam Info Good Morning All - I am looking to take my Licensing exam and get my HAM / Radio Operator's license. I was told there was one online for about $80.00 but I don't have the first clue where to look. Is it somewhere on the ARRL web page, or somewhere else I need to be looking? Also - how long are the licenses good for? If you point me in the right direction - I can handle it from there. :-) Thanks! John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl. com/2dtngmn
RE: [Repeater-Builder] Re: Icom OPC-617 Cable
VHF 128 channels. Programmed with CF-100 program software -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com]on Behalf Of Duane Hall Sent: Thursday, July 22, 2010 1:05 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Icom OPC-617 Cable IC-F121 Icom On 7/22/2010 11:28 AM, Gary W. Gibbs wrote: What model radio is this ? NIMS: 100 200 300 400 700 800 Arrl Extra Class VE HAZ MAT- A O sent from my blackberry mobile device
Re: [Repeater-Builder] OT: Licensing Exam Info
Yep, blew the numbers. 97 for hams and 95 for the other services. That is what I get for not paying attention. Around 1972 I took the comercial class exam. I thought I knew enough for the second class at that time and it cost $ 1.00 more for the first class. Decided that for only $ 1 as I had to drive about 40 miles to the exam place I would try it just to see. I did manage to get the first class. Never used it, but had it just incase I needed it. NOw they have a general type license and it is not really needed for much frow what I have been told. At that time there were no exect qustions and answers, just typical ones. About that same time I took the technician ham test and passed it. I was too lazy to work on the code and not that interisted in the low bands either. About 20 years later I was working a job that gave me lots of free time if nothing broke so I got some tapes and started on the code again. Passed the Advanced test (at that time the only differance in the general and tech was the code speed so when a tech passed the 13 wpm he was automatically a general). Took about another year to get the code speed up to 20 wpm. I never did get a chance to study the written test but looked over the questions one time. Anyway passed it the first time. From: chuck wolf cwolf...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Sun, July 25, 2010 8:47:00 AM Subject: Re: [Repeater-Builder] OT: Licensing Exam Info 2. Part 95 is not the Amateur part. It is Part 97. FCC Part 95 is for Personal Radio Services (GMRS, FRS, Radio Control Radio Services, Citizens Band, etc.) http://www.gpo.gov/fdsys/pkg/CFR-2009-title47-vol5/pdf/CFR-2009-title47-vol5-part95.pdf FCC Part 97 is for Amateur Radio Services.
RE: [Repeater-Builder] Repeater receiver testing
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] Repeater Receiver Testing
I have this lowband Micor receiver that I would like to check the adjacent channel rejection. I have two calibrated signal generators, and a calibrated spectrum analyzer (if needed). Can I do the measurements with this equipment? If so, how? Resistor divider network between the two sig gens? Thanks, Tim
[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: Repeater receiver testing
If you are attempting to verify a manufacturer's specification, the TIA-603 procedure should be used. If you are serious about that, you should probably acquire TSB-88 in addition to TIA-603. Here is a link to a presentation that discusses adjacent channel testing and explains the roles of the various standards documents: http://www.apcointl.org/frequency/documents/W09-olson.ppt Jeff has summarized the procedure correctly with the exception that the current procedure utilizes a two-tone modulation for the interefering signal. This test requires that the signal generator ustilized for the interefering signal have exceptional phase noise performance or the test results will be inaccurate. There are a number of suitable high-end generators such as the Aeroflex 2041. I doubt if the signal generation function of any service monitor is suitable. If you are simply wanting to compare various recever models for a particular application such as a repeater receiver, an alternative would be to use the actual repeater transmitter as the interferer. Connect it to a suitable load with a signal tap and attenuator configured to sample the signal and feed into the receiver test in place of the second signal generator. Here is another summary of a process similar to the TIA-603: ADJACENT CHANNEL REJECTION Method of Measurement Terminate the audio output of the receiver in a load specified by the manufacturer, and make measurements using a C-message weighted filter. (a) Connect two RF signal generators equally coupled to the receiver antenna input terminals through a suitable matching network. Set the first RF signal generator to the assigned channel frequency and modulate it with a 1004 Hz tone at 60% of the maximum permissible peak frequency deviation. Switch the second generator off. Adjust the first RF signal generator level to produce a 12 dB SINAD measurement at the audio-output terminals of the receive path. Record the RF signal level and increase this first RF signal generator output by 3 dB. (b) Set the frequency of the second RF signal generator to the adjacent channel above the frequency of the first RF signal generator and modulate it simultaneously with two tones, one at 650 Hz at a deviation of 50% of the maximum permissible frequency deviation and another at 2200 Hz at a deviation of 50% of the maximum permissible frequency deviation. The level of each of the two tones should be set to 50% of the generator's modulator input level specification. The deviation of the RF signal generator should be set to 100% of the maximum permissible frequency deviation. Adjust the level of the second RF signal generator to reduce the SINAD measurement back to 12 dB. Record the RF signal level. (c) Repeat step (b) with the frequency of the second RF signal generator set to the adjacent channel below the frequency of the first RF signal generator. (d) Calculate the ratios, in decibels (dB), of the undesired signal levels measured in steps (b) and (c) to the reference level obtained in step (a). The smaller of these ratios for the above and below channel undesired signals is the adjacent channel rejection. -- --- In Repeater-Builder@yahoogroups.com, tahrens301 tahr...@... wrote: 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: Repeater receiver testing
Hi Nj902, Well, I'm not trying to be exacting in the measurement, I'm just trying to track down a desense issue in the system. I figured I'd look at how the receiver does with the adjacent (transmitter) signal injected directly into the rx input port. The spectrum analyzer hooked up to the RX port on the duplexer shows -55dBm, which should be down sufficiently enough not to be heard by the receiver. I'm running the duplexer into a dummy load, and all interconnecting cables are double shielded. However, the desense is so severe that I am beginning to think there may be something wrong in the RX. Hence, the question. Just trying to find that silver bullet. Got any spares? Thanks, Tim
Re: [Repeater-Builder] Re: Repeater receiver testing
Hi you beat me to it, I would suggest a duplexer problem as -55dB isn't a lot you should have ideally better than 80dB. It also could be the fact that you are running too much tx pwr, have you tried dropping it down. 73 Steve, M1SWB(UK) - Original Message - From: Tim tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Sunday, July 25, 2010 9:24 PM Subject: [Repeater-Builder] Re: Repeater receiver testing Hi Nj902, Well, I'm not trying to be exacting in the measurement, I'm just trying to track down a desense issue in the system. I figured I'd look at how the receiver does with the adjacent (transmitter) signal injected directly into the rx input port. The spectrum analyzer hooked up to the RX port on the duplexer shows -55dBm, which should be down sufficiently enough not to be heard by the receiver. I'm running the duplexer into a dummy load, and all interconnecting cables are double shielded. However, the desense is so severe that I am beginning to think there may be something wrong in the RX. Hence, the question. Just trying to find that silver bullet. Got any spares? Thanks, Tim Yahoo! Groups Links
[Repeater-Builder] Re: Repeater receiver testing
The issue for repeater receiver desense is the same basic issue that affects the bench test. For the bench test if the generator used for the adjacent channel signal has too much phase noise - that noise will degrade the receiver before the carrier level can be raised to the manufacturer's spec. With a repeater - if the transmitter sideband noise is too great - or the duplexer's attenuation of that noise is insufficient - then the receiver will be degraded. Measuring the transmit carrier level at the receiver input - not so hard. Measuring the transmit sideband noise at the receiver input - not so easy. Your issue is probably due to not enough TX sideband noise suppression. We're assuming you used all double-shielded coax, but look at everything - maybe there is a faulty coax or connector allowing leakage to cause the degradation. --- In Repeater-Builder@yahoogroups.com, Tim tahr...@... wrote: Hi Nj902, Well, I'm not trying to be exacting in the measurement, I'm just trying to track down a desense issue in the system. I figured I'd look at how the receiver does with the adjacent (transmitter) signal injected directly into the rx input port. The spectrum analyzer hooked up to the RX port on the duplexer shows -55dBm, which should be down sufficiently enough not to be heard by the receiver. I'm running the duplexer into a dummy load, and all interconnecting cables are double shielded. However, the desense is so severe that I am beginning to think there may be something wrong in the RX. Hence, the question. Just trying to find that silver bullet. Got any spares? Thanks, Tim
Re: [Repeater-Builder] Re: Repeater receiver testing
Hi Steve, Running 80 watts into the duplexer, getting 50 out. Getting about 102dB notch out of the duplexers. From a previous thread a couple of days ago, the consensus was that -50 was fine for this receiver. I hooked up my IC-706 to the TX port, and even at 5w, I was getting significant desense. Figured I'd try take one variable on at a time... RX first. The RX was given to me, already crystalled 'tuned' up... it was a voting receiver at a multi-site repeater. Not sure if had any 'special' modifications done to it! Thanks, Tim
[Repeater-Builder] Re: Repeater receiver testing
Hi 902, Understand about the sideband noise, but I figured at a MHz away, it probably wouldn't be an issue. Getting the same performance out of both sides of the duplexer ... about 102dB notch 1.5dB attenuation. Using RG142 for all interconnects, except from TX/RX to duplexer, and those are RG-214. Guess I could hookup a signal generator with a -50dBm signal into the RX, and measure it at the input with a high impedance probe hooked to the spectrum analyzer. Take that measurement, and then hook up the duplexer key it up. Check the measurement again see if it's the same, or more. Thanks, Tim
Re: [Repeater-Builder] Re: Repeater receiver testing
Been following this thread for a while, some thoughts in random order: If I remember correctly you said that you are using the 1 5/8 heliax notches as your duplexer. If I also remember correctly others have reported problems of many sorts with these homebrew devices. 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. You probably should also look at the TX signal to check for spurs. If the RX has the extender circuit installed, turn it off and rerun your test. It could be that the extender is tuned to a frequency near the TX or a low level output from the TX. I also have had duplexers that look good with a tracking generator but fail under TX power. Milt N3LTQ Quoting Tim tahr...@swtexas.net: Hi 902, Understand about the sideband noise, but I figured at a MHz away, it probably wouldn't be an issue. Getting the same performance out of both sides of the duplexer ... about 102dB notch 1.5dB attenuation. Using RG142 for all interconnects, except from TX/RX to duplexer, and those are RG-214. Guess I could hookup a signal generator with a -50dBm signal into the RX, and measure it at the input with a high impedance probe hooked to the spectrum analyzer. Take that measurement, and then hook up the duplexer key it up. Check the measurement again see if it's the same, or more. Thanks, Tim Yahoo! Groups Links
[Repeater-Builder] Anybody have a clue ?
Photo here: www.repeater-builder.com/wa6ilq/Motorola-S-1350-C-WATT-METER-with-500W-500-1000-MHZ.jpg Anybody know who made the watt meter in the photo for Moto ? Did that company market it under their own name? The HT220 switch handle on the right side is the forward-reverse selector switch. Did Moto actually use that know/handle as a stock item? Or has someone along the line lost the original knob? Mike WA6ILQ
Re: [Repeater-Builder] Anybody have a clue ?
The HT220 is an element lock/release. The forward /reverse is the little silver buttons on either side. I have one but not sure WHO make it for moto On Sun, Jul 25, 2010 at 2:37 PM, Mike Morris wa6...@gmail.com wrote: Photo here: www.repeater-builder.com/wa6ilq/Motorola-S-1350-C-WATT-METER-with-500W-500-1000-MHZ.jpg Anybody know who made the watt meter in the photo for Moto ? Did that company market it under their own name? The HT220 switch handle on the right side is the forward-reverse selector switch. Did Moto actually use that know/handle as a stock item? Or has someone along the line lost the original knob? Mike WA6ILQ Yahoo! Groups Links
Re: [Repeater-Builder] Anybody have a clue ?
The power elements look like the same ones I have for my R2002 comm analyzer. Tim
[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: Repeater receiver testing
Hi again Tim what you could try is this, put a signal gen on the tx port and see what the isolation is on the rx port, don't forget to put a dummy 50ohm load on the ant port Steve - Original Message - From: Tim tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Sunday, July 25, 2010 10:28 PM Subject: [Repeater-Builder] Re: Repeater receiver testing Hi 902, Understand about the sideband noise, but I figured at a MHz away, it probably wouldn't be an issue. Getting the same performance out of both sides of the duplexer ... about 102dB notch 1.5dB attenuation. Using RG142 for all interconnects, except from TX/RX to duplexer, and those are RG-214. Guess I could hookup a signal generator with a -50dBm signal into the RX, and measure it at the input with a high impedance probe hooked to the spectrum analyzer. Take that measurement, and then hook up the duplexer key it up. Check the measurement again see if it's the same, or more. Thanks, Tim Yahoo! Groups Links
RE: [Repeater-Builder] Re: Repeater receiver testing
Hi you beat me to it, I would suggest a duplexer problem as -55dB isn't a lot you should have ideally better than 80dB. It also could be the fact that you are running too much tx pwr, have you tried dropping it down. 73 Steve, M1SWB(UK) He said he measured the Tx carrier at the Rx port of the duplexer at -55 dBm; he didn't say he had 55 dB of isolation...
Re: [Repeater-Builder] Re: Repeater receiver testing
Hi OH right 30w loss is not right. You maybe getting -102db notch but it is the isolation between the tx an rx ports that count, you need better than 80db. I know of some 6mtr repeaters in the UK that use the heliax duplexers and get better than -90db isolation with insertion losses a round 1.5dB. We are limited to 25w erp so usual tx in is about 25w and out of the duplexer around 20w 73 Steve - Original Message - From: Tim tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Sunday, July 25, 2010 10:23 PM Subject: Re: [Repeater-Builder] Re: Repeater receiver testing Hi Steve, Running 80 watts into the duplexer, getting 50 out. Getting about 102dB notch out of the duplexers. From a previous thread a couple of days ago, the consensus was that -50 was fine for this receiver. I hooked up my IC-706 to the TX port, and even at 5w, I was getting significant desense. Figured I'd try take one variable on at a time... RX first. The RX was given to me, already crystalled 'tuned' up... it was a voting receiver at a multi-site repeater. Not sure if had any 'special' modifications done to it! Thanks, Tim Yahoo! Groups Links
Re: [Repeater-Builder] Re: Repeater receiver testing
Hi Jeff yes I know -55db is I think around 399 microvolts which will flatten any receiver, he needs to know the actual isolation between the tx and rx ports. I assume that the notch figure Tim mentions is the actual notch of each filter, which is why in my later mail I suggested doing an isolation test with sig gen and analyser 73 Steve - Original Message - From: Jeff DePolo j...@broadsci.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, July 25, 2010 11:43 PM Subject: RE: [Repeater-Builder] Re: Repeater receiver testing Hi you beat me to it, I would suggest a duplexer problem as -55dB isn't a lot you should have ideally better than 80dB. It also could be the fact that you are running too much tx pwr, have you tried dropping it down. 73 Steve, M1SWB(UK) He said he measured the Tx carrier at the Rx port of the duplexer at -55 dBm; he didn't say he had 55 dB of isolation... Yahoo! Groups Links
RE: [Repeater-Builder] Motorola R-2200A User Manual
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
RE: [Repeater-Builder] Re: Repeater receiver testing
Hi Jeff yes I know -55db is I think around 399 microvolts No, you're still missing it. He said -55 dBm (m = milliwatts), not -55 dB. which will flatten any receiver -55 dBm at 1 MHz offset isn't going to bother any half-decent receiver. A decent receiver would have 100 dB of adjacent-channel selectivity (that would be 20 kHz away on lowband), so if we assume the sensitivity is -117 dBm (0.3 uV), it should tolerate a signal int the vicity of -17 dBm at only 20 kHz away with only slight degradation. At 1 MHz away, a good lowband receiver with a real front end will tolerate much, much more, probably on the order of 0 dBm (over 2/10ths of a volt). 80 watts TPO = +49 dBm. He's measuring -55 dBm at the receive port, so he has 104 dB of carrier supression, way way way more than is necessary for a Micor at 1 MHz split. --- Jeff WN3A
Re: [Repeater-Builder] Anybody have a clue ?
Allow me to show my age ... To me, the HT-220 is/was a Xtal Controlled Ht !! The Forward/Reverse switch is the buttons on the side. The flat knob on the right is the element locking mechanism. I have three of these and a box full of elements. They are quite accurate, equaling a Bird 43. The high power elements (1 kw and up) just don't exist. 73, Dick, W1KSZ -Original Message- From: Mike Morris wa6...@gmail.com Sent: Jul 25, 2010 3:37 PM To: repeater-builder@yahoogroups.com Subject: [Repeater-Builder] Anybody have a clue ? Photo here: www.repeater-builder.com/wa6ilq/Motorola-S-1350-C-WATT-METER-with-500W-500-1000-MHZ.jpg Anybody know who made the watt meter in the photo for Moto ? Did that company market it under their own name? The HT220 switch handle on the right side is the forward-reverse selector switch. Did Moto actually use that know/handle as a stock item? Or has someone along the line lost the original knob? Mike WA6ILQ Yahoo! Groups Links
Re: [Repeater-Builder] Anybody have a clue ?
On 7/25/2010 2:37 PM, Mike Morris wrote: Photo here: www.repeater-builder.com/wa6ilq/Motorola-S-1350-C-WATT-METER-with-500W-500-1000-MHZ.jpg Anybody know who made the watt meter in the photo for Moto ? I believe this was a Motorola fabricated item. It was also used with several generations of their service monitors and in some high power base stations as a sensing element. I believe the basic design was done by the Government Equipment Group (division) in Phoenix. Did that company market it under their own name? Motorola ;-) The HT220 switch handle on the right side is the forward-reverse selector switch. Did Moto actually use that know/handle as a stock item? Or has someone along the line lost the original knob? Dunno. Mike WA6ILQ -- mailto:o...@ozindfw.net Oz - N1OZ POB 93167 Southlake, TX 76092 (Near DFW Airport)
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.
[Repeater-Builder] Re: Repeater receiver testing
Tim, It appears to me that your measurement procedure is correct - and that the results you have gotten would normally be sufficient isolation to allow desense-free duplex operation. If you have some attenuators available - or better yet - a switchable [in 1 dB increments] attenuator - there is a test you could try. Assuming you are running your desense test with the repeater terminated in a quality 50 ohm resistive power load and feeding your generator in through an iso-T, you establish a sensitivity reference [e.g. 12 dBS] then key the repeater transmitter and readjust the generator for the same reference. The difference in readings is the amount of desense. Insert an attenuator in the receiver line between the duplexer's receive port and the receiver's antenna port. Start with about 10 dB. You should then require 10 dB more signal from your generator to achieve your initial quieting reference. Now when you key the transmitter again measure the desense. The attenuator gives you the equivalent of that much additional isolation. Your desense should be correspondingly less. With a switchable attenuator you can determine just how much more isolation you need. The results you get - whether they 'track' or aren't linear may give some clue as to the nature of the issue. WB0EMU --- In Repeater-Builder@yahoogroups.com, Tim tahr...@... wrote: ...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)
Re: [Repeater-Builder] Anybody have a clue ?
The S-1350 wattmeter was designed by an RF engineer at the Motorola Schaumburg Parts Department and was built at the Motorola Schaumburg Parts Department. The RF power calibration standards for RF certifications of the S-1350 were supplied by the Motorola Schaumburg Instrumentation Department to the parts department by myself. Allan Crites WA9ZZU From: Oz-in-DFW li...@ozindfw.net To: Repeater-Builder@yahoogroups.com Sent: Sun, July 25, 2010 9:34:35 PM Subject: Re: [Repeater-Builder] Anybody have a clue ? On 7/25/2010 2:37 PM, Mike Morris wrote: Photo here: www.repeater- builder.com/ wa6ilq/Motorola- S-1350-C- WATT-METER- with-500W- 500-1000- MHZ.jpg Anybody know who made the watt meter in the photo for Moto ? I believe this was a Motorola fabricated item. It was also used with several generations of their service monitors and in some high power base stations as a sensing element. I believe the basic design was done by the Government Equipment Group (division) in Phoenix. Did that company market it under their own name? Motorola ;-) The HT220 switch handle on the right side is the forward-reverse selector switch. Did Moto actually use that know/handle as a stock item? Or has someone along the line lost the original knob? Dunno. Mike WA6ILQ -- mailto:o...@ozindfw. net Oz - N1OZ POB 93167 Southlake, TX 76092 (Near DFW Airport)
Re: [Repeater-Builder] Recommendations for a Voter Link
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] Anybody have a clue ?
Hello Mike. I am not sure who made it for Motorola but they did use the frequency knob from the portables to lock the The sensor is/was designed to be left in the feedline and all you have to do is slide the sensor into the meter, lock it in place and you are ready to go. I used to have one of those with lots of different elements and it worked great. Butch, KE7FEL/r On Sun, Jul 25, 2010 at 1:37 PM, Mike Morris wa6...@gmail.com wrote: Photo here: www.repeater-builder.com/wa6ilq/Motorola-S-1350-C-WATT-METER-with-500W-500-1000-MHZ.jpg Anybody know who made the watt meter in the photo for Moto ? Did that company market it under their own name? The HT220 switch handle on the right side is the forward-reverse selector switch. Did Moto actually use that know/handle as a stock item? Or has someone along the line lost the original knob? Mike WA6ILQ
[Repeater-Builder] Re: Repeater receiver testing
Hi Nj, Thanks for the info. That's one test I'll be trying tomorrow. I did a bit of snooping in the IF chain with a scope probe my spectrum analyzer, and found that at the back end of the xtal filter chain/amplifiers, I saw two signals, one a MHz above the desired receive frequency, and it was quite large. So, either I was introducing it into the receiver.. always possible, or there is something big time wrong with the RX. I have another receiver strip, and I will re-tune it tomorrow see if anything changes. I'll keep all posted on the outcome. Thanks, Tim
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-buil...@yahoogroups.com] On Behalf Of ac6vj
Sent: Monday, June 28, 2010 9:41 AM
To: Repeater-Builder@yahoogroups.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}
--- In Repeater-Builder@yahoogroups.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
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