Re: QUANTAR VHF Audio Interface...
Hi Chris, Thanks for your comments and observations. On my repeater... no, I don't run the audio out to 5 kHz, but at the same time I don't have the sharp 2.5 or 3 kHz cutoff that many systems have.? I've learned over the years that if you're running through various pieces of equipment that have the same roll off or cutoff, you'll have ringing.? All of my system, and it is a stand alone repeater, and not tied to other systems, is wideband audio.? The audio is only "band-stopped" just prior to going into the modulator, But at the same time, I don't want that to be a sharp cutoff.? I do regularly monitor my occupied bandwidth, and only once have I had a complaint from a neighbor which I immediately took care of by lowering the deviation a tad.? That was caused by a previous mis-adjustment on my part. As far as running "flat audio," not sure what that means as there have been so many opinions on that term.? In the case of my system, I de-emphasize the audio out of the receiver so that I'm only dealing with "flat audio" from all my sources and then pre-emphasizing the audio just ahead of the modulator.? Keep in mind, the modulator is direct FM. Regarding two-way radio, pre and de-emphasis is always a compromise, as there really is no common standard and each manufacturer seems to have their own standard.? Even in the case of phase modulation, which has it's own natural pre-emphasis - the breaking point, if you will, is different between various equipment manufacturers.? It may not be very scientific, but I use a pot to adjust de-emphasis and adjust to what sounds pleasant.? It's a compromise. Anyway, it is "Ham Radio" and thankfully we are not tied to the two-way business "standards".? We can strive to make things sound pleasant and at the same time use good engineering practices.? I do not bow to the Motorola gods and I don't speak Motorolaese.? :) I'm sure we'll have more discussion on this, which is a good and pleasant thing. Burt, K6OQK
I've done flat audio in the pass but always use a RC filter to roll off above 3-4khz...no need to go higher as the energy in that area is QUITE low and not needed..I've made GE MVPs rptrs with flat audio and FM on the exciter where it coupled to an ACC RC850 passed Alinco Digital with no problem...had to back off the radio deviation a little...it would clip thru the rptr at high deviation..
?
I've ran Quantars in flat audio mode using the RSS settings and found great results..but I would never use 5kHz audio b/w...the Carson rule of B/W tells me not to anyway ..it exceeds 16-20K easily.
?
I am not only a ham but a LMR and Broadcast Engineer for the last 45+ yrs..
Yeah I read all about the early repeaters in Bill Pasternak's book and other sources...I like keeping up with history like that. :)?
?
BTW I hate the idiots on HF trying HIFI SSB...WE ARE NOT broadcasters...makes me smdh
?
Just saying..
?
?
Chris
WB5ITT
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Re: QUANTAR VHF Audio Interface...
Jim, Thanks for your reply, and no, for some reason I did not see it earlier.? Are pins 9 & 34 a balanced pair?? How are they coupled in so as to have wide band audio? Electronically balanced, transformer, or each and unbalanced input?? I had seen those on another sheet and wasn't sure if they were data only and not capable of passing analog audio. Thanks, Burt, K6OQK
Then you did not see my reply.
The general transmit input is uses for simulcast. It passes DC to 10 KHz with no issues.
Connector 17, (50 pin telco)Pins 9 and 34
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Re: Sinclair R-302C duplexer info
What did you get before the move, you may need to replace inter can cabling or other components to go 20mhz
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Re: Repeater Horror Stories
? This is very ingenuous... You get my Award for the effort. ? I think you mean genius ? ?
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Re: Repeater Horror Stories
On Mon, Oct 24, 2022 at 08:10 AM, J Donovan wrote:
It is very difficult to chase a signal that only appears when you are transmitting.
This is very ingenuous... You get my Award for the effort.
Paul? w0rw
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Re: QUANTAR VHF Audio Interface...
Don't know about you men, but at 79 yrs old my hearing aides make all, especially Motorola speakers sound more intelligible, much less muffled, and because of? the aide's high frequency pre-emphasis, audio at 3KHz now sounds plenty crisp and clear!
John W1GPO
On 10/25/2022 12:55 AM Burt K6OQK <biwa@...> wrote:
Ok guys...
You bring up a lot of interesting points, but nothing new to me.? Let me say that I've been in the 2-Meter repeater business for over 60 years.? I've always prided myself in good performance and good audio quality.? To me, and to many others, 300-3000 Hz audio doesn't cut it.? As it was said, this is Amateur Radio.? :)
The reason I want to access the wide band audio is to stay away from the typical narrow sound of many repeaters.? If you're in the southern California area, take a listen to the W6MEP 2-Meter repeater on 147.24 MHz.? It's very compatible with all 5 kHz dev radios, commercial and others.? The audio out of the completely home brewed receiver is wide band - 50 Hz to a little over 6 kHz? There is a very narrow P.L. notch filter in the controller.? The transmitter is direct FM. The modulation index is barely 1.? I do have audio processing in the system in the way of an Orban FM 8100A Optimod. (I do have the stereo turned off.) I have a low pass filter between the output of the processing and the input to the modulator.? The deviation is 4-4.5 kHz and is very consistent without sucking up noise between words.? The repeater is very transparent except that the transmitted audio is pretty consistent.? I get a lot of comments on how unusually clean and consistent the repeater sounds.
My plan is to add a Quantar receiver and transmitter, although the home brewed receiver, which was originally built in 1974 and recently updated, is a fairly high performance receiver and can perform better than Mt. Wilson will allow.? I intend to feed the QUANTAR transmitter from the Optimod and keep my 1960 vintage controller, which sometimes makes noise like a Pachinko machine.? It has personality and sounds good.? Besides, I'm having a great time doing all this stuff.? To each their own.
I'm presently fighting intermittent power line noise which is believed to be coming from the 37,000 volt line coming up the mountain very near our location.? There is also an intermittent intermod problem involving our own transmitter and there's no audio, not even ours, to give a clue as to what the other signal/s might be, just narrow band noise when it happens.? It comes and goes like flipping a switch on and off.? I suspect a transmitter that's spewing wide band noise.? I've sat there with a spectrum analyzer till I'm blue in the face.? It doesn't want to happen when I'm there.? Why is that?
You can go to and look up W6MEP to see a picture of the repeater as it is now and how it looked when Art, W6MEP built his amazing contraption back in the 1950's.? You can also go to to see my first repeater and the silliness I went through in having a good time.
I do appreciate the comments and I know where you're coming from, but I also know where I'm going and still remain a good neighbor to adjacent channel repeaters.
Thank you for putting up with me.
Burt, K6OQK
|
Re: QUANTAR VHF Audio Interface...
I've done flat audio in the pass but always use a RC filter to roll off above 3-4khz...no need to go higher as the energy in that area is QUITE low and not needed..I've made GE MVPs rptrs with flat audio and FM on the exciter where it coupled to an ACC RC850 passed Alinco Digital with no problem...had to back off the radio deviation a little...it would clip thru the rptr at high deviation..
I've ran Quantars in flat audio mode using the RSS settings and found great results..but I would never use 5kHz audio b/w...the Carson rule of B/W tells me not to anyway ..it exceeds 16-20K easily.
I am not only a ham but a LMR and Broadcast Engineer for the last 45+ yrs.. Yeah I read all about the early repeaters in Bill Pasternak's book and other sources...I like keeping up with history like that. :)?
BTW I hate the idiots on HF trying HIFI SSB...WE ARE NOT broadcasters...makes me smdh
Just saying..
Chris WB5ITT?
On Mon, Oct 24, 2022, 11:55 PM Burt K6OQK < biwa@...> wrote: Ok guys...
You bring up a lot of interesting points, but nothing new to me.? Let me say that I've been in the 2-Meter repeater business for over 60 years.? I've always prided myself in good performance and good audio quality.? To me, and to many others, 300-3000 Hz audio doesn't cut it.? As it was said, this is Amateur Radio.? :)
The reason I want to access the wide band audio is to stay away from the typical narrow sound of many repeaters.? If you're in the southern California area, take a listen to the W6MEP 2-Meter repeater on 147.24 MHz.? It's very compatible with all 5 kHz dev radios, commercial and others.? The audio out of the completely home brewed receiver is wide band - 50 Hz to a little over 6 kHz? There is a very narrow P.L. notch filter in the controller.? The transmitter is direct FM. The modulation index is barely 1.? I do have audio processing in the system in the way of an Orban FM 8100A Optimod. (I do have the stereo turned off.) I have a low pass filter between the output of the processing and the input to the modulator.? The deviation is 4-4.5 kHz and is very consistent without sucking up noise between words.? The repeater is very transparent except that the transmitted audio is pretty consistent.? I get a lot of comments on how unusually clean and consistent the repeater sounds.
My plan is to add a Quantar receiver and transmitter, although the home brewed receiver, which was originally built in 1974 and recently updated, is a fairly high performance receiver and can perform better than Mt. Wilson will allow.? I intend to feed the QUANTAR transmitter from the Optimod and keep my 1960 vintage controller, which sometimes makes noise like a Pachinko machine.? It has personality and sounds good.? Besides, I'm having a great time doing all this stuff.? To each their own.
I'm presently fighting intermittent power line noise which is believed to be coming from the 37,000 volt line coming up the mountain very near our location.? There is also an intermittent intermod problem involving our own transmitter and there's no audio, not even ours, to give a clue as to what the other signal/s might be, just narrow band noise when it happens.? It comes and goes like flipping a switch on and off.? I suspect a transmitter that's spewing wide band noise.? I've sat there with a spectrum analyzer till I'm blue in the face.? It doesn't want to happen when I'm there.? Why is that?
You can go to and look up W6MEP to see a picture of the repeater as it is now and how it looked when Art, W6MEP built his amazing contraption back in the 1950's.? You can also go to to see my first repeater and the silliness I went through in having a good time.
I do appreciate the comments and I know where you're coming from, but I also know where I'm going and still remain a good neighbor to adjacent channel repeaters.
Thank you for putting up with me.
Burt, K6OQK
|
i have a R1225 that i use a laptop running windows 98 running using a real RIB and Cable and CPS 4.0 and since mine didn't?have a control head what i use to program it is the?Knob/Mic port?assembly?from a GM300 head since i had one that the LED?assembly was blown on and that works great then just use a PC jumper on the ON/OFF pins hope you get it too work soon
I had that problem in the past with virtual.? Found an old win 7 32 bit laptop and it worked
kt7az
|
There¡¯s several Moto RSS/CPS that will appear to be working on 64 bit hardware loaded with a 32 bit Windows or 32 bit virtual machine, but they won¡¯t communicate with the radio. Been there with the MTS and MCS radios. Requires actual 32 bit hardware in the computer.? tnx Mike / K5JR? Alpharetta GA
toggle quoted message
Show quoted text
On Oct 24, 2022, at 7:45 PM, Matt Wagner <mwaggy@...> wrote: ? Thanks, all, for the feedback.
I could have been more clear, but beyond the weird interface with just an RJ-45 on the front, I do have a remote head (actually two) to try with ribbon cables. Neither helps the situation, though.
I have noticed that, with the USB-to-serial adapter plugged into the powered-up radio, I get some flashing on both the TX and RX LEDs on the cable, whereas trying it without the radio on gives me just a few blinks of the TX light. It makes me think that there is some communication taking place with the radio, just not properly.
I am using CPS Version 4.0 on 32-bit XP, but it is running in VirtualBox on a 64-bit Windows 10 machine. Let me see if my old native-XP Toughbook powers up at all. I had hoped the R1225 was new enough to not be upset by a fast computer, but maybe something between that or running in a VM is the problem.
I too am on using Ver 4.0 Rss?
Next is to pin out the connector you have to ensure the pins talk with the read/write lines on the chassis connector - major reservations here on this being an issue -
Many of the R1225 I maintain today are with an XP machine and 4.0 with a native serial (no USB excuses) and the rib loves talking every time
There are extra R1225 heads around if one is needed to troubleshoot
Jason
I have had trouble with R1225's in the past, just like you describe.
Are you using the Version 4 software?
If an earlier version, then it won't like XP.
If you can find someone with WIN 98 on an old slow machine and a REAL Motorola rib and cable, that is
a last resort to try with the earlier versions.
I have had very poor luck with the USB to serial adapters.
Gave up on them years ago.
|
Re: QUANTAR VHF Audio Interface...
Ok guys...
You bring up a lot of interesting points, but nothing new to me.? Let me say that I've been in the 2-Meter repeater business for over 60 years.? I've always prided myself in good performance and good audio quality.? To me, and to many others, 300-3000 Hz audio doesn't cut it.? As it was said, this is Amateur Radio.? :)
The reason I want to access the wide band audio is to stay away from the typical narrow sound of many repeaters.? If you're in the southern California area, take a listen to the W6MEP 2-Meter repeater on 147.24 MHz.? It's very compatible with all 5 kHz dev radios, commercial and others.? The audio out of the completely home brewed receiver is wide band - 50 Hz to a little over 6 kHz? There is a very narrow P.L. notch filter in the controller.? The transmitter is direct FM. The modulation index is barely 1.? I do have audio processing in the system in the way of an Orban FM 8100A Optimod. (I do have the stereo turned off.) I have a low pass filter between the output of the processing and the input to the modulator.? The deviation is 4-4.5 kHz and is very consistent without sucking up noise between words.? The repeater is very transparent except that the transmitted audio is pretty consistent.? I get a lot of comments on how unusually clean and consistent the repeater sounds.
My plan is to add a Quantar receiver and transmitter, although the home brewed receiver, which was originally built in 1974 and recently updated, is a fairly high performance receiver and can perform better than Mt. Wilson will allow.? I intend to feed the QUANTAR transmitter from the Optimod and keep my 1960 vintage controller, which sometimes makes noise like a Pachinko machine.? It has personality and sounds good.? Besides, I'm having a great time doing all this stuff.? To each their own.
I'm presently fighting intermittent power line noise which is believed to be coming from the 37,000 volt line coming up the mountain very near our location.? There is also an intermittent intermod problem involving our own transmitter and there's no audio, not even ours, to give a clue as to what the other signal/s might be, just narrow band noise when it happens.? It comes and goes like flipping a switch on and off.? I suspect a transmitter that's spewing wide band noise.? I've sat there with a spectrum analyzer till I'm blue in the face.? It doesn't want to happen when I'm there.? Why is that?
You can go to and look up W6MEP to see a picture of the repeater as it is now and how it looked when Art, W6MEP built his amazing contraption back in the 1950's.? You can also go to to see my first repeater and the silliness I went through in having a good time.
I do appreciate the comments and I know where you're coming from, but I also know where I'm going and still remain a good neighbor to adjacent channel repeaters.
Thank you for putting up with me.
Burt, K6OQK
|
Re: QUANTAR VHF Audio Interface...
When I first saw the question, I scratched my head and went on to other things.? It looked wierd.? Then I remembered why.?
If you are actually going to feed audio up to 6 khz. to the modulator, where does it actually go after that???
Even if you reduce the deviation and the pre-emphasis to keep the bandwidth down to a normal FM channel, anyone trying
to recieve it will have to modify the reciever so it won't squelch itself out trying to recieve.?
?
Sounds confusing, but the typical 16kF3 reciever needs to have a 20khz bandwidth in the IF to allow for drift and to prevent
the reciever from squelching out.? The back-end was made to roll off above 3khz to the speech amp and the squelch amp will
be listening for noise above that to keep the squelch closed.?
If this is for a link radio on the 2m ham band, how were you planning to keep the bandwidth to a normal ham channel?? If this is
for a ham voice repeater, everyone will have to modify their radios to use it.? If for commercial, you would have to re-engineer the
Quantar and apply for a new FCC certification.
Or are you planning on jamming out some people?? If you remove the splatter filter, you could concievably take up the whole
2m band depending on the actual bandwidth of the PA.? Or you could do away with the Quantar entirely and move up to a FM
stereo broadcast station with extra muxed channels.
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Re: QUANTAR VHF Audio Interface...
Jim,
Thank you. You saved me a whole lot of
work!
Tom K8TB
On 10/24/2022 9:35 PM, Jim W7RY via
groups.io wrote:
toggle quoted message
Show quoted text
Then you did not see my reply.
The general transmit input is uses for simulcast. It passes DC
to 10 KHz with no issues.
Connector 17, (50 pin telco)Pins 9 and 34
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Re: QUANTAR VHF Audio Interface...
Burt,
Interestingly enough, I was hoping to
look at a Quantar this winter to get to that line and see how flat
it is. It has DC, so a cap is called for, and I don't know what
the source impedance of that line is, so a good op-amp with the
proper build out resistor might be needed.
And then, that receiver. The Quantar
uses that special IC, but I looked at the schematic briefly, and
it looks like the IC delivers I/Q audio. Well, a simple I/Q
decoder should give us flat audio, me thinks. I would like to end
up with a repeater that is flat from 50 hz to 5000 hz. A notch
filter on the rx Pl tone, and an external audio limiter. Yes, we
only need 300-2500 for communications. But, this is ham radio !
Tom (now retired) K8TB
On 10/24/2022 9:25 PM, Burt K6OQK
wrote:
toggle quoted message
Show quoted text
If you look at the exciter schematic you will see pin-78 of P/O
P-102 .? It's called, "VCO AUDIO" and goes into the 6 kHz splatter
filter circuitry and then directly to the "Varactor modulator,"
CR3250.? I may have to break down and access this by modifying the
back plane board.? Being lazy, I was hoping for something simple.
Burt, K6OQK
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Re: QUANTAR VHF Audio Interface...
Then you did not see my reply.
The general transmit input is uses for simulcast. It passes DC to
10 KHz with no issues.
Connector 17, (50 pin telco)Pins 9 and 34
Thanks, 73, Jim W7RY
On 10/24/2022 8:25 PM, Burt K6OQK
wrote:
toggle quoted message
Show quoted text
All,
Thank you for your replies.? However, I need wideband analog
input, not the typical/normal 250-3000 Hz audio.? The wideband
audio is from darn near DC to 5+ kHz.
I was hoping the "Aux TX Audio"? on pin 5 of the 50 pin connector
would be it, but it appears to only be 250-3000 Hz, or less.
Unfortunately I only have the service manual in pdf form.? Trying
to find what I'm looking for in that is giving me a krik in my
neck and my peepers are becoming crossed.?
If you look at the exciter schematic you will see pin-78 of P/O
P-102 .? It's called, "VCO AUDIO" and goes into the 6 kHz splatter
filter circuitry and then directly to the "Varactor modulator,"
CR3250.? I may have to break down and access this by modifying the
back plane board.? Being lazy, I was hoping for something simple.
Burt, K6OQK
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Sinclair R-302C duplexer info
Does anyone have the specifications and tune up instructions for the Sinclair R-302C duplexer? I have one that I am trying to retune one from 463/468.8MHz to 441/446.8MHz. Right now I am getting only -60dB notch on the new frequencies and I do not know if that is normal or not.
Ben Stapp KB5ZO
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Re: QUANTAR VHF Audio Interface...
I'll try to check a copy of the manual here at the HQ in Austin tomorrow....my manual is back at my office in Beaumont.
Chris WB5ITT CET III Texas Department of Public Safety?
On Mon, Oct 24, 2022, 8:25 PM Burt K6OQK < biwa@...> wrote: All,
Thank you for your replies.? However, I need wideband analog input, not the typical/normal 250-3000 Hz audio.? The wideband audio is from darn near DC to 5+ kHz.
I was hoping the "Aux TX Audio"? on pin 5 of the 50 pin connector would be it, but it appears to only be 250-3000 Hz, or less.
Unfortunately I only have the service manual in pdf form.? Trying to find what I'm looking for in that is giving me a krik in my neck and my peepers are becoming crossed.?
If you look at the exciter schematic you will see pin-78 of P/O P-102 .? It's called, "VCO AUDIO" and goes into the 6 kHz splatter filter circuitry and then directly to the "Varactor modulator," CR3250.? I may have to break down and access this by modifying the back plane board.? Being lazy, I was hoping for something simple.
Burt, K6OQK
|
Re: QUANTAR VHF Audio Interface...
Fwiw. I have used Mark dannons cables for numerous projects and have several in service since 2013 no issues.? ?
N3ssl?
|
Re: QUANTAR VHF Audio Interface...
All,
Thank you for your replies.? However, I need wideband analog input, not the typical/normal 250-3000 Hz audio.? The wideband audio is from darn near DC to 5+ kHz.
I was hoping the "Aux TX Audio"? on pin 5 of the 50 pin connector would be it, but it appears to only be 250-3000 Hz, or less.
Unfortunately I only have the service manual in pdf form.? Trying to find what I'm looking for in that is giving me a krik in my neck and my peepers are becoming crossed.?
If you look at the exciter schematic you will see pin-78 of P/O P-102 .? It's called, "VCO AUDIO" and goes into the 6 kHz splatter filter circuitry and then directly to the "Varactor modulator," CR3250.? I may have to break down and access this by modifying the back plane board.? Being lazy, I was hoping for something simple.
Burt, K6OQK
|
I had that problem in the past with virtual. ?Found an old win 7 32 bit laptop and it worked
kt7az
|
Thanks, all, for the feedback.
I could have been more clear, but beyond the weird interface with just an RJ-45 on the front, I do have a remote head (actually two) to try with ribbon cables. Neither helps the situation, though.
I have noticed that, with the USB-to-serial adapter plugged into the powered-up radio, I get some flashing on both the TX and RX LEDs on the cable, whereas trying it without the radio on gives me just a few blinks of the TX light. It makes me think that there is some communication taking place with the radio, just not properly.
I am using CPS Version 4.0 on 32-bit XP, but it is running in VirtualBox on a 64-bit Windows 10 machine. Let me see if my old native-XP Toughbook powers up at all. I had hoped the R1225 was new enough to not be upset by a fast computer, but maybe something between that or running in a VM is the problem.
I too am on using Ver 4.0 Rss?
Next is to pin out the connector you have to ensure the pins talk with the read/write lines on the chassis connector - major reservations here on this being an issue -
Many of the R1225 I maintain today are with an XP machine and 4.0 with a native serial (no USB excuses) and the rib loves talking every time
There are extra R1225 heads around if one is needed to troubleshoot
Jason
I have had trouble with R1225's in the past, just like you describe.
Are you using the Version 4 software?
If an earlier version, then it won't like XP.
If you can find someone with WIN 98 on an old slow machine and a REAL Motorola rib and cable, that is
a last resort to try with the earlier versions.
I have had very poor luck with the USB to serial adapters.
Gave up on them years ago.
|
Burt K6OQK
Chris Boone WB5ITT
Kevin Bednar
KT7AZ
Matt Wagner