Re: T4XB/R4B Transceive problem
? ? ?I did essentially the same thing to keep from loading down the circuit. I¡¯ll report on the progress but for the next couple of weeks my priorities are going in another direction.? ? ? ?Everyone have a very Merry Christmas and a safe and Happy New Year.?
Tony - W9JXN?
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On Dec 22, 2024, at 3:29?PM, Gary WB6OGD via groups.io <winbladgary@...> wrote:
? There is no 50KHz in the transmitter.
BUT, Richard points out an important thing.? 50KHz in the R-4s are adjustable... not by much, but with component
drift or other problems, the 50KHz BFO MIGHT be off. Also Steve's method of using a receiver is better than hooking in a frequency counter.? The counter can load the circuit and force it off frequency.? I have lately been using my tinySA, just lay a probe over the circuit and see everything. Don't give up, let us know what you find, 73, Gary WB6OGD
On Sun, Dec 22, 2024 at 1:11?PM Richard Knoppow via <1oldlens1= [email protected]> wrote: ? ? Its been a long time since I aligned my T4XB/R4B but I think maybe
there is an alignment problem, not a bad filter or bad crystal. The idea
is to set the? 50 Khz LO so that the carrier falls at the same place on
the upper and lower slopes of the filter. Can by done by ear or by
measuring the amount the carrier is reduced from the peak. This is the
LO in the transmitter. The LO in the receiver is set to match it using
C-61 to get the "Tweet" zero beat. The color coded crystals were meant
to give matched temperature drift but with the age of the crystals that
is probably no longer valid and is, in any case, not a big deal. It may
be necessary to reset C-61 occasionally. In my twins the colors do not
match or maybe there are no colors but the zero beat doesn't change.
? ? ?Because the? 50 Khz band pass filter in the R4B is adjustable the
exact LO frequency does not matter. The adjustment is given in the
_transmitter_ book even though its for the receiver.
? ? ?I just think the crystal is probably OK and this is a red herring.
? ? ?I've found that? you must study both handbooks carefully, read
everything even if you don't think its relevant. Also, if you don't have
Gary Barrell's (never sure of the spelling) CD for the B line GET IT,
and read or at least look at everything in it.
? ? ?I think these are very good pieces of equipment and the performance
is excellent.
? ? ?Due to work done on the house (which I rent) I lost my workshop, no
longer power there. Puts a crimp in my work. Will fix this eventually.
Otherwise I would poke at my twins to see what I can find.
On 12/22/2024 12:47 PM, Steve Wedge, W1ES/4 via wrote:
> I¡¯ve seen mixed ones like this before. Just production variations. Set
> C2 to exactly 5645.000 and check the results.
>
> The method from the manual is a pain, quite honestly. Hans didn¡¯t have
> access to lab grade counters back I. The day.
>
> Steve Wedge, W1ES
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Drake L4/L7 power supply upgrade board for sale
Hello,
?
I have a fully assembled, tested, but never used Heathkit Shop power supply upgrade board for Drake amps for sale. Price is $125.00 plus shipping from 23418. Details and pictures are available on request.
?
73,
Garry - K4OR
|
Re: T4XB/R4B Transceive problem
There is no 50KHz in the transmitter.
BUT, Richard points out an important thing.? 50KHz in the R-4s are adjustable... not by much, but with component
drift or other problems, the 50KHz BFO MIGHT be off. Also Steve's method of using a receiver is better than hooking in a frequency counter.? The counter can load the circuit and force it off frequency.? I have lately been using my tinySA, just lay a probe over the circuit and see everything. Don't give up, let us know what you find, 73, Gary WB6OGD
On Sun, Dec 22, 2024 at 1:11?PM Richard Knoppow via <1oldlens1= [email protected]> wrote: ? ? Its been a long time since I aligned my T4XB/R4B but I think maybe
there is an alignment problem, not a bad filter or bad crystal. The idea
is to set the? 50 Khz LO so that the carrier falls at the same place on
the upper and lower slopes of the filter. Can by done by ear or by
measuring the amount the carrier is reduced from the peak. This is the
LO in the transmitter. The LO in the receiver is set to match it using
C-61 to get the "Tweet" zero beat. The color coded crystals were meant
to give matched temperature drift but with the age of the crystals that
is probably no longer valid and is, in any case, not a big deal. It may
be necessary to reset C-61 occasionally. In my twins the colors do not
match or maybe there are no colors but the zero beat doesn't change.
? ? ?Because the? 50 Khz band pass filter in the R4B is adjustable the
exact LO frequency does not matter. The adjustment is given in the
_transmitter_ book even though its for the receiver.
? ? ?I just think the crystal is probably OK and this is a red herring.
? ? ?I've found that? you must study both handbooks carefully, read
everything even if you don't think its relevant. Also, if you don't have
Gary Barrell's (never sure of the spelling) CD for the B line GET IT,
and read or at least look at everything in it.
? ? ?I think these are very good pieces of equipment and the performance
is excellent.
? ? ?Due to work done on the house (which I rent) I lost my workshop, no
longer power there. Puts a crimp in my work. Will fix this eventually.
Otherwise I would poke at my twins to see what I can find.
On 12/22/2024 12:47 PM, Steve Wedge, W1ES/4 via wrote:
> I¡¯ve seen mixed ones like this before. Just production variations. Set
> C2 to exactly 5645.000 and check the results.
>
> The method from the manual is a pain, quite honestly. Hans didn¡¯t have
> access to lab grade counters back I. The day.
>
> Steve Wedge, W1ES
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: T4XB/R4B Transceive problem
Disregard my post. There ARE two filters in the T4XB, upper and lower sideband. The curves are shown in Fig.17, which shows the "carrier" intercept at about 40 db below peak.
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On 12/22/2024 1:11 PM, Richard Knoppow via groups.io wrote: ?? Its been a long time since I aligned my T4XB/R4B but I think maybe there is an alignment problem, not a bad filter or bad crystal. The idea is to set the? 50 Khz LO so that the carrier falls at the same place on the upper and lower slopes of the filter. Can by done by ear or by measuring the amount the carrier is reduced from the peak. This is the LO in the transmitter. The LO in the receiver is set to match it using
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: T4XB/R4B Transceive problem
Its been a long time since I aligned my T4XB/R4B but I think maybe there is an alignment problem, not a bad filter or bad crystal. The idea is to set the 50 Khz LO so that the carrier falls at the same place on the upper and lower slopes of the filter. Can by done by ear or by measuring the amount the carrier is reduced from the peak. This is the LO in the transmitter. The LO in the receiver is set to match it using C-61 to get the "Tweet" zero beat. The color coded crystals were meant to give matched temperature drift but with the age of the crystals that is probably no longer valid and is, in any case, not a big deal. It may be necessary to reset C-61 occasionally. In my twins the colors do not match or maybe there are no colors but the zero beat doesn't change.
Because the 50 Khz band pass filter in the R4B is adjustable the exact LO frequency does not matter. The adjustment is given in the _transmitter_ book even though its for the receiver.
I just think the crystal is probably OK and this is a red herring.
I've found that you must study both handbooks carefully, read everything even if you don't think its relevant. Also, if you don't have Gary Barrell's (never sure of the spelling) CD for the B line GET IT, and read or at least look at everything in it.
I think these are very good pieces of equipment and the performance is excellent.
Due to work done on the house (which I rent) I lost my workshop, no longer power there. Puts a crimp in my work. Will fix this eventually. Otherwise I would poke at my twins to see what I can find.
toggle quoted message
Show quoted text
On 12/22/2024 12:47 PM, Steve Wedge, W1ES/4 via groups.io wrote: I¡¯ve seen mixed ones like this before. Just production variations. Set C2 to exactly 5645.000 and check the results.
The method from the manual is a pain, quite honestly. Hans didn¡¯t have access to lab grade counters back I. The day.
Steve Wedge, W1ES
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: T4XB/R4B Transceive problem
I¡¯ve seen mixed ones like this before. Just production variations. Set C2 to exactly 5645.000 and check the results.?
The method from the manual is a pain, quite honestly. Hans didn¡¯t have access to lab grade counters back I. The day.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Sun, Dec 22, 2024 at 15:14, Tony Sokol via groups.io < tony.sokol@...> wrote: Steve,
? ? ?I agree but stranger things have happened. I noticed that the two folders in this T4X have two different colors. If you look closely you will see that one on top is blue and the other on the bottom is silver. Someone else may have been chasing the problem before me.?
Tony
On Dec 22, 2024, at 9:57?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
?
The chance of both filters drifting by the same amount is pretty low.?
I had to take a wire and put it near the CO and listen on my receiver.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Sun, Dec 22, 2024 at 10:21, Bob Loving <
bob.loving@...> wrote:
Tony, can you also use the counter to read the frequency of the carrier oscillator in the T-4XB? It should indicate 5.645000-MHz (+/- 10 Hz?).
Bob K9JU
On Sunday, December 22, 2024 at 01:31:59 AM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Well I put the R4B on the bench tonight (with Linda¡¯s help) and the verdict is in. The R4B¡¯s crystal is cleared of any wrong doing.?
? ? ?That would tend to make the culprit appear to be one or both T4XB filters having changed significantly. At this point I¡¯m thinking of putting them back on the shelf. They operate fine when used as separates. It¡¯s just the transceive function that is off. I may just offer them here in the near future since I have the TR7/RV75 and a TR4C both of which work great thanks to a good friend of mine. ?
Tony
On Dec 21, 2024, at 5:18?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that.
? ? ?Frank Krozel
Life Member, ARRL
? ? (630) 924-1600
kg9hfrank@...
|
Re: T4XB/R4B Transceive problem
The filters may be from two different manufacturers or a change in outer can color by one supplier. Offhand, I don't know if different suppliers for Drake used different can colors.
73, Bob K9JU
Maryville, TN
On Sunday, December 22, 2024 at 03:15:07 PM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Steve, ? ? ?I agree but stranger things have happened. I noticed that the two folders in this T4X have two different colors. If you look closely you will see that one on top is blue and the other on the bottom is silver. Someone else may have been chasing the problem before me.?
Tony
On Dec 22, 2024, at 9:57?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
? The chance of both filters drifting by the same amount is pretty low.?
I had to take a wire and put it near the CO and listen on my receiver.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Sun, Dec 22, 2024 at 10:21, Bob Loving < bob.loving@...> wrote:
Tony, can you also use the counter to read the frequency of the carrier oscillator in the T-4XB? It should indicate 5.645000-MHz (+/- 10 Hz?).
Bob K9JU
On Sunday, December 22, 2024 at 01:31:59 AM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Well I put the R4B on the bench tonight (with Linda¡¯s help) and the verdict is in. The R4B¡¯s crystal is cleared of any wrong doing.?
? ? ?That would tend to make the culprit appear to be one or both T4XB filters having changed significantly. At this point I¡¯m thinking of putting them back on the shelf. They operate fine when used as separates. It¡¯s just the transceive function that is off. I may just offer them here in the near future since I have the TR7/RV75 and a TR4C both of which work great thanks to a good friend of mine. ?
Tony
On Dec 21, 2024, at 5:18?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that.
? ? ?Frank Krozel
Life Member, ARRL
? ? (630) 924-1600
kg9hfrank@...
|
Re: T4XB/R4B Transceive problem
Steve, ? ? ?I agree but stranger things have happened. I noticed that the two folders in this T4X have two different colors. If you look closely you will see that one on top is blue and the other on the bottom is silver. Someone else may have been chasing the problem before me.?
Tony
toggle quoted message
Show quoted text
On Dec 22, 2024, at 9:57?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
? The chance of both filters drifting by the same amount is pretty low.?
I had to take a wire and put it near the CO and listen on my receiver.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Sun, Dec 22, 2024 at 10:21, Bob Loving < bob.loving@...> wrote:
Tony, can you also use the counter to read the frequency of the carrier oscillator in the T-4XB? It should indicate 5.645000-MHz (+/- 10 Hz?).
Bob K9JU
On Sunday, December 22, 2024 at 01:31:59 AM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Well I put the R4B on the bench tonight (with Linda¡¯s help) and the verdict is in. The R4B¡¯s crystal is cleared of any wrong doing.?
? ? ?That would tend to make the culprit appear to be one or both T4XB filters having changed significantly. At this point I¡¯m thinking of putting them back on the shelf. They operate fine when used as separates. It¡¯s just the transceive function that is off. I may just offer them here in the near future since I have the TR7/RV75 and a TR4C both of which work great thanks to a good friend of mine. ?
Tony
On Dec 21, 2024, at 5:18?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that.
? ? ?Frank Krozel
Life Member, ARRL
? ? (630) 924-1600
kg9hfrank@...
|
Re: T4XB/R4B Transceive problem
The chance of both filters drifting by the same amount is pretty low.?
I had to take a wire and put it near the CO and listen on my receiver.?
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Sun, Dec 22, 2024 at 10:21, Bob Loving < bob.loving@...> wrote:
Tony, can you also use the counter to read the frequency of the carrier oscillator in the T-4XB? It should indicate 5.645000-MHz (+/- 10 Hz?).
Bob K9JU
On Sunday, December 22, 2024 at 01:31:59 AM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Well I put the R4B on the bench tonight (with Linda¡¯s help) and the verdict is in. The R4B¡¯s crystal is cleared of any wrong doing.?
? ? ?That would tend to make the culprit appear to be one or both T4XB filters having changed significantly. At this point I¡¯m thinking of putting them back on the shelf. They operate fine when used as separates. It¡¯s just the transceive function that is off. I may just offer them here in the near future since I have the TR7/RV75 and a TR4C both of which work great thanks to a good friend of mine. ?
Tony
On Dec 21, 2024, at 5:18?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that.
? ? ?Frank Krozel
Life Member, ARRL
? ? (630) 924-1600
kg9hfrank@...
|
Re: T4XB/R4B Transceive problem
Tony, can you also use the counter to read the frequency of the carrier oscillator in the T-4XB? It should indicate 5.645000-MHz (+/- 10 Hz?).
Bob K9JU
On Sunday, December 22, 2024 at 01:31:59 AM EST, Tony Sokol via groups.io <tony.sokol@...> wrote:
Well I put the R4B on the bench tonight (with Linda¡¯s help) and the verdict is in. The R4B¡¯s crystal is cleared of any wrong doing.?
? ? ?That would tend to make the culprit appear to be one or both T4XB filters having changed significantly. At this point I¡¯m thinking of putting them back on the shelf. They operate fine when used as separates. It¡¯s just the transceive function that is off. I may just offer them here in the near future since I have the TR7/RV75 and a TR4C both of which work great thanks to a good friend of mine. ?
Tony
On Dec 21, 2024, at 5:18?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that. ? ? ?Frank Krozel Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
|
Re: T4XB/R4B Transceive problem
Well I put the R4B on the bench tonight (with Linda¡¯s help) and the verdict is in. The R4B¡¯s crystal is cleared of any wrong doing.?
? ? ?That would tend to make the culprit appear to be one or both T4XB filters having changed significantly. At this point I¡¯m thinking of putting them back on the shelf. They operate fine when used as separates. It¡¯s just the transceive function that is off. I may just offer them here in the near future since I have the TR7/RV75 and a TR4C both of which work great thanks to a good friend of mine. ?
Tony
toggle quoted message
Show quoted text
On Dec 21, 2024, at 5:18?PM, Bob Loving via groups.io <bob.loving@...> wrote:
?
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that. ? ? ?Frank Krozel Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
|
Re: Wanted: 1500 Hz filter
Makes me wonder if Frank could produce a new 48.050-MHz filter for the TR7.?
Bob K9JU
On Saturday, December 21, 2024 at 07:54:23 PM EST, Floyd - K8AC via groups.io <floydsense@...> wrote:
Frank made up a 1500 Hz filter for me and just received it today.? Works perfectly.? I highly recommend Noble Radio for filters.
?
73, Floyd - K8AC
|
Re: TR7 Digital Display +300Hz.
First check the??check the 10.0 volt supply. It needs to be dead on before any other adjustments.
Then check the 40 MHz reference oscillator. That controls all operating frequencies, including the display reading, in the TR7.
There are not a lot of other things that can cause a small error in frequency.?
The TR7 is a true frequency counter, unlike most radios. That means it takes the premix to the first mixer and subtracts it From the 48.05 MHz IF to give actual operating frequency. Only an error in the timebase (the 40 MHz reference) can cause errant display readings.
Gary
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On Dec 21, 2024, at 7:49?PM, Robin K4IDC via groups.io <RobinK4IDC@...> wrote:
A certain TR7 shows 300Hz. high on the digital display; tuning to the known correct frequency?for several nets such that the received audio sounds correct always results in a 300Hz. indication to the high side. Received reports confirm the same; transmitted audio sounds great when the digi display is?+300. Is there an easy solution? Google search isn't much help.
Thanks,
Robin Midgett K4IDC
|
TR7 Digital Display +300Hz.
A certain TR7 shows 300Hz. high on the digital display; tuning to the known correct frequency?for several nets such that the received audio sounds correct always results in a 300Hz. indication to the high side. Received reports confirm the same; transmitted audio sounds great when the digi display is?+300. Is there an easy solution? Google search isn't much help.
Thanks,
Robin Midgett K4IDC
|
Re: Wanted: 1500 Hz filter
Frank made up a 1500 Hz filter for me and just received it today.? Works perfectly.? I highly recommend Noble Radio for filters.
?
73, Floyd - K8AC
|
Re: T4XB/R4B Transceive problem
Tony, AK4K Crystals has the 5.595-MHz crystal available as a stock item. Taking into inflation, the $32.00 price tag isn't "that" bad!
Bob K9JU
Maryville, TN
On Saturday, December 21, 2024 at 12:50:43 PM EST, kg9hfrank@... via groups.io <kg9hfrank@...> wrote:
I used to use Motorola Crystal Ovens from T43-GGV, etc, 6VDC, 2 in series run off of 12VDC to do that. ? ? ?Frank Krozel Life Member, ARRL ? ? (630) 924-1600 kg9hfrank@...
|
If you have good 500 kHz on the board make sure the protection circuit is working properly. Q9011 should be biased on to provide GND to the LED's. If not, none of them will work.
|
Re: R4C need PCB foil diagram
On 2024-12-21 06:13, Jay W6CJ via groups.io wrote: Throw away radios.. just like cell phones and all new gadgets.
I am sure loving my old ancient Kenwoods and Drakes... easy and
cheap to fix, modify and enjoy!
*** Indeed. I had a QSO on one of the forever discussion groups on 40M. The net control was flabbergasted that I had managed to fix a Signal/One. I tried to explain that it was really a fairly straightforward radio, and nowhere near the same ballpark of difficulty as the modern stuff, which generally consists of: 1 big board... with a giant 200-pin ASIC in the middle. - Jerry, KF6VB
|
Scratch that. I just looked at the schematic again (since I just finished stitching the three scanned images back into a single schematic) and the Full Coverage section (U9001 through U9008) gets its 5V from the Digital Control board underneath the DR7. This would not make the counter go dark. Look for the 500 KHz reference signal as was suggested in another post. You may have some Parent Board Molexia going on somewhere. Thinking about that schematic after I went to the trouble of stitching it, it occurs to me that it might be sensible to also break it up into four distinct sections: Full Coverage Input Counter (dividers and timebase) LED Display and Drive That's a project for another day as I just know I would feel compelled to clean up some areas that have poor readability. Right now I need to go play with some RF. On Sat, 21 Dec 2024 13:44:35 -0600 "Jim Shorney via groups.io" <jimNU0C@...> wrote: the common 5V rail coming from U9033. -- 73 -Jim NU0C
|
Just as a side note, 9001 through 9008 are not related to the frequency counter. They deal with PLL N codes that are passed from the Digital Control Board to the Translator Board. That's not discount the possibility that you might have an open trace somewhere in the common 5V rail coming from U9033. My rule with boards this old is "never trust a via". That includes pass-throughs at the Molex male pins and IC pins. On Sat, 21 Dec 2024 15:16:41 -0400 "Jim Harris via groups.io" <radiove1rb@...> wrote: Okay, I have been working on the DR7 board and I found that the following
I.C's do not have any Plus 5 volts DC on them. They are U9001, U0002,
U9003, U9004, U9005, U9006, U9007, and U9008. -- 73 -Jim NU0C
|
Gary WB6OGD
Robin K4IDC
Floyd - K8AC
Jeff W7KNX
Jim Shorney