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XV222 RX is Dead, Need Advice

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k2qo

XV222 RX is Dead, Need Advice

During the recent September VHF contest I could only hear the absolute
strongest local stations on the XV222/K3 in my rover. It worked FB in June.
My XV432 worked just OK as usual. Stations told me I was the loudest signal
on the 222 band so the TX side is fine.

I put it on the bench and connected my Elecraft N-Gen. When turned on I
could barely detect an increase in noise. Tried the same on my XV432 and it
went from S0/1 to a solid S9.

I'm guessing that I somehow blew up U1 (an ERA6) and/or Q3 (an ATF 34143). I
don't have a good scope, RF generator, or RF voltmeter but kinda think
replacing both will fix my XV. A bad relay is an option too.

Thoughts? I'd like to fix it to have for a spare as I plan on moving
non-BigE transverters for 222 and 432.

73,
Mark K2QO
NF2RS/R for the September VHF

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Re: XV222 RX is Dead, Need Advice

Mark
You can check the performance of your XV222 receiver amplifiers with only a common voltmeter.

Take off the top cover of the transverter, check the voltage between TP2 and ground (should be between 200 to 275 millivolts). That measures part of the source voltage of Q3, the first receiver amplifier.

Find R16 (a 120 ohm resistor) and measure the voltage to ground on each side of the resistor. One side should be 12 volts, the other should be about 5 volts. That measures the series dropping resistor for U1, the second receiver amplifier. R16 will normally be very warm to the touch.

If those measurements are correct, the problem is most likely elsewhere.

You can check the condition of the local oscillator by measuring the voltage between TP1 and ground. It should be between 1.0 and 1.5 volts.

The part and test point locations are shown in the Transverter Owners Manual, page A-4, available on the Elecraft web site.
Good luck!
73, Mike, W3IP

On Thursday, September 17, 2020, 8:58:35 PM EDT, k2qo <[hidden email]> wrote:

During the recent September VHF contest I could only hear the absolute
strongest local stations on the XV222/K3 in my rover. It worked FB in June.
My XV432 worked just OK as usual. Stations told me I was the loudest signal
on the 222 band so the TX side is fine.

I put it on the bench and connected my Elecraft N-Gen. When turned on I
could barely detect an increase in noise. Tried the same on my XV432 and it
went from S0/1 to a solid S9.

I'm guessing that I somehow blew up U1 (an ERA6) and/or Q3 (an ATF 34143). I
don't have a good scope, RF generator, or RF voltmeter but kinda think
replacing both will fix my XV. A bad relay is an option too.

Thoughts? I'd like to fix it to have for a spare as I plan on moving
non-BigE transverters for 222 and 432.

73,
Mark K2QO
NF2RS/R for the September VHF

--
Sent from: http://elecraft.365791.n2.nabble.com/
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k2qo

Re: XV222 RX is Dead, Need Advice

Thanks Mike. I built this along with the XV432 a LONG time ago :-) The 432 unit had loads of issues. My rover partner, a EE grad from 1964 who designed military radios and antennas for a living was not impressed with either of these transverters, especially the XV432. For a hobby, he checks the math in QEX articles. One time he told me that the author mis-applied Maxwell’s equation and he ran his own set of differential equations to prove the point.

On to the my results:

> On Sep 17, 2020, at 9:44 PM, M Cresap <[hidden email]> wrote:
>
> Take off the top cover of the transverter, check the voltage between TP2 and ground (should be between 200 to 275 millivolts). That measures part of the source voltage of Q3, the first receiver amplifier.

65mV

>
> Find R16 (a 120 ohm resistor) and measure the voltage to ground on each side of the resistor. One side should be 12 volts, the other should be about 5 volts. That measures the series dropping resistor for U1, the second receiver amplifier. R16 will normally be very warm to the touch.

13.8 and 4.9V

>
> If those measurements are correct, the problem is most likely elsewhere.
>
> You can check the condition of the local oscillator by measuring the voltage between TP1 and ground. It should be between 1.0 and 1.5 volts.

0.92V

Additionally, TP1 is 0.76V, not the minimum 1V.
The output pin of U1 is 0V, not 3.0-6.0V.

>
>
>
>
> On Thursday, September 17, 2020, 8:58:35 PM EDT, k2qo <[hidden email]> wrote:
>
>
> During the recent September VHF contest I could only hear the absolute
> strongest local stations on the XV222/K3 in my rover. It worked FB in June.
> My XV432 worked just OK as usual. Stations told me I was the loudest signal
> on the 222 band so the TX side is fine.
>
> I put it on the bench and connected my Elecraft N-Gen. When turned on I
> could barely detect an increase in noise. Tried the same on my XV432 and it
> went from S0/1 to a solid S9.
>
> I'm guessing that I somehow blew up U1 (an ERA6) and/or Q3 (an ATF 34143). I
> don't have a good scope, RF generator, or RF voltmeter but kinda think
> replacing both will fix my XV. A bad relay is an option too.
>
> Thoughts? I'd like to fix it to have for a spare as I plan on moving
> non-BigE transverters for 222 and 432.
>
> 73,
> Mark K2QO
> NF2RS/R for the September VHF
>
>
>
> --
> Sent from: http://elecraft.365791.n2.nabble.com/ <http://elecraft.365791.n2.nabble.com/>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft <http://mailman.qth.net/mailman/listinfo/elecraft>
> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm>
> Post: mailto:[hidden email] <mailto:[hidden email]>
>
> This list hosted by: http://www.qsl.net <http://www.qsl.net/>
> Please help support this email list: http://www.qsl.net/donate.html <http://www.qsl.net/donate.html>
> Message delivered to [hidden email] <mailto:[hidden email]>

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Don Wilhelm

Re: XV222 RX is Dead, Need Advice

In reply to this post by k2qo

Mark,

Replacing those components will normally restore receive.

73
Don W3FPR

On 9/17/2020 8:57 PM, k2qo wrote:

> During the recent September VHF contest I could only hear the absolute
> strongest local stations on the XV222/K3 in my rover. It worked FB in June.
> My XV432 worked just OK as usual. Stations told me I was the loudest signal
> on the 222 band so the TX side is fine.
>
> I put it on the bench and connected my Elecraft N-Gen. When turned on I
> could barely detect an increase in noise. Tried the same on my XV432 and it
> went from S0/1 to a solid S9.
>
> I'm guessing that I somehow blew up U1 (an ERA6) and/or Q3 (an ATF 34143). I
> don't have a good scope, RF generator, or RF voltmeter but kinda think
> replacing both will fix my XV. A bad relay is an option too.
>

k2qo

Re: XV222 RX is Dead, Need Advice

Thanks Don,

I had a MAR6 in stock and installed it after breakfast. There is now a noticeable change in RX noise with the noise bridge turned on, but nowhere near what is needed, so I’ll order a Q3.

73,
Mark K2QO
FN03ra

> On Sep 18, 2020, at 12:23 AM, Don Wilhelm <[hidden email]> wrote:
>
> Mark,
>
> Replacing those components will normally restore receive.
>
> 73
> Don W3FPR
>
> On 9/17/2020 8:57 PM, k2qo wrote:
>> During the recent September VHF contest I could only hear the absolute
>> strongest local stations on the XV222/K3 in my rover. It worked FB in June.
>> My XV432 worked just OK as usual. Stations told me I was the loudest signal
>> on the 222 band so the TX side is fine.
>> I put it on the bench and connected my Elecraft N-Gen. When turned on I
>> could barely detect an increase in noise. Tried the same on my XV432 and it
>> went from S0/1 to a solid S9.
>> I'm guessing that I somehow blew up U1 (an ERA6) and/or Q3 (an ATF 34143). I
>> don't have a good scope, RF generator, or RF voltmeter but kinda think
>> replacing both will fix my XV. A bad relay is an option too.

k2qo

Re: XV222 RX is Dead, Need Advice

In reply to this post by k2qo

Mike,

I’ve done some of these mods, but not all.

I replaced the MAR6 this morning and it now hears a little better, but the S-meter on the K3 is not moving. Q3 is next.

AND I JUST REMEMBERED!!! When I was setting up the rover before the contest, I was keying all the equipment with the antennas attached to check power output, listen to local beacons, etc. The XV222 was receiving OK. I then transmitted and in a few seconds blew the 5A fuse in my WestMountain Radio distribution block. I intended on commenting it to a 10A PP connector but “missed”. I replaced the fuse and went roving.

I wonder whether maybe that caused some TX energy to get back into the RX circuit? Oh well, the MAR6 is replaced and I’ll get a new ATF.

The crazy thing is that I did not think of this until last night when I had everything on the bench.

73,
Mark K2QO
FN03ra

> On Sep 17, 2020, at 10:54 PM, M Cresap <[hidden email]> wrote:
>
> Hi Mark
>
> Yes, the XV432 transverter needed a few fixes to work reliably. NT4RT wrote an excellent article on how to improve the performance of the XV432 (which I see you have found already). My XV432 is extensively modified with my own fixes, most of NT4RT's fixes, and K9YC's recommended "Pin 1 problem" fixes (i.e. rebuild the back panel).
>
> For the XV222, the first thing I would do to hook up your noise generator to the RF input and try to adjust R13 for about 250 mV on TP2. See if that improves your ability to receive the noise generator. I found that the gain varies a LOT as R13 is adjusted. Be careful not to mistakenly tweak R10, which is nearby! Don't ask how I know that :-(
>
> Let me know if that helps.
>
> 73, Mike, W3IP
>
> On Thursday, September 17, 2020, 10:29:59 PM EDT, Mark Adams <[hidden email]> wrote:
>
>
> Thanks Mike. I built this along with the XV432 a LONG time ago :-) The 432 unit had loads of issues. My rover partner, a EE grad from 1964 who designed military radios and antennas for a living was not impressed with either of these transverters, especially the XV432. For a hobby, he checks the math in QEX articles. One time he told me that the author mis-applied Maxwell’s equation and he ran his own set of differential equations to prove the point.
>
> On to the my results:
>
>
>> On Sep 17, 2020, at 9:44 PM, M Cresap <[hidden email] <mailto:[hidden email]>> wrote:
>>
>> Take off the top cover of the transverter, check the voltage between TP2 and ground (should be between 200 to 275 millivolts). That measures part of the source voltage of Q3, the first receiver amplifier.
>
>
> 65mV
>
>
>>
>> Find R16 (a 120 ohm resistor) and measure the voltage to ground on each side of the resistor. One side should be 12 volts, the other should be about 5 volts. That measures the series dropping resistor for U1, the second receiver amplifier. R16 will normally be very warm to the touch.
>
>
> 13.8 and 4.9V
>
>
>>
>> If those measurements are correct, the problem is most likely elsewhere.
>>
>> You can check the condition of the local oscillator by measuring the voltage between TP1 and ground. It should be between 1.0 and 1.5 volts.
>
>
> 0.92V
>
>
> Additionally, TP1 is 0.76V, not the minimum 1V.
> The output pin of U1 is 0V, not 3.0-6.0V.
>
>
>
>
>>
>>
>>
>>
>> On Thursday, September 17, 2020, 8:58:35 PM EDT, k2qo <[hidden email] <mailto:[hidden email]>> wrote:
>>
>>
>> During the recent September VHF contest I could only hear the absolute
>> strongest local stations on the XV222/K3 in my rover. It worked FB in June.
>> My XV432 worked just OK as usual. Stations told me I was the loudest signal
>> on the 222 band so the TX side is fine.
>>
>> I put it on the bench and connected my Elecraft N-Gen. When turned on I
>> could barely detect an increase in noise. Tried the same on my XV432 and it
>> went from S0/1 to a solid S9.
>>
>> I'm guessing that I somehow blew up U1 (an ERA6) and/or Q3 (an ATF 34143). I
>> don't have a good scope, RF generator, or RF voltmeter but kinda think
>> replacing both will fix my XV. A bad relay is an option too.
>>
>> Thoughts? I'd like to fix it to have for a spare as I plan on moving
>> non-BigE transverters for 222 and 432.
>>
>> 73,
>> Mark K2QO
>> NF2RS/R for the September VHF
>>
>>
>>
>> --
>> Sent from: http://elecraft.365791.n2.nabble.com/ <http://elecraft.365791.n2.nabble.com/>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft <http://mailman.qth.net/mailman/listinfo/elecraft>
>> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm>
>> Post: mailto:[hidden email] <mailto:[hidden email]>
>>
>> This list hosted by: http://www.qsl.net <http://www.qsl.net/>
>> Please help support this email list: http://www.qsl.net/donate.html <http://www.qsl.net/donate.html>
>> Message delivered to [hidden email] <mailto:[hidden email]>
>
>

k2qo

Re: XV222 RX is Dead, Need Advice

In reply to this post by k2qo

Don and gang,

I replaced Q3, U1 and the ADEX mixer. Results? Transmit works FB as before
and the RX still has no sensitivity. No change at all. I ran through the
setup related to the RX section and one thing stands out.

Part VIII: RX Input Alignment
Trimmer cap C1 has no effect on the AC voltage at the phone output
connector. This is the same result I had before replacing the 3 parts.

I think I may be down to signal tracing starting at the N connector. But
without a list of test points and voltages, this may be a nonproductive
PITA.

The next step is to sell this unit for parts or buy a working used XV222 so
I can backward engineer a solution.

73,
Mark K2QO

--
Sent from: http://elecraft.365791.n2.nabble.com/
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Don Wilhelm

Re: XV222 RX is Dead, Need Advice

Mark,

Sorry about your failed effort. There is little in the RX path other
than Q3 and U1 that is not also used in TX.

If you have equipment that can do signal tracing at 222MHz, just trace
the signal path. There should be a significant increase in RF voltage
at the output of Q3 and more at the output of U1. If not, check to be
certain K1 has not been damaged. K1 should be available from Elecraft
since it is used in the XV144 which is still in production.

73,
Don W3FPR

On 9/25/2020 1:21 PM, k2qo wrote:

> Don and gang,
>
> I replaced Q3, U1 and the ADEX mixer. Results? Transmit works FB as before
> and the RX still has no sensitivity. No change at all. I ran through the
> setup related to the RX section and one thing stands out.
>
> Part VIII: RX Input Alignment
> Trimmer cap C1 has no effect on the AC voltage at the phone output
> connector. This is the same result I had before replacing the 3 parts.
>
> I think I may be down to signal tracing starting at the N connector. But
> without a list of test points and voltages, this may be a nonproductive
> PITA.
>

qrp5w

Re: XV222 RX is Dead, Need Advice

In reply to this post by k2qo

Mark,

Do you have a schematic for the XV222? I looked on their site and
could not come up with one.

72

Howard Kraus, K2UD

-----------------------------------------From: "Don Wilhelm"
To: "k2qo"
Cc:
Sent: Friday September 25 2020 2:44:03PM
Subject: Re: [Elecraft] XV222 RX is Dead, Need Advice

Mark,

Sorry about your failed effort. There is little in the RX path other
than Q3 and U1 that is not also used in TX.

If you have equipment that can do signal tracing at 222MHz, just
trace
the signal path. There should be a significant increase in RF voltage

at the output of Q3 and more at the output of U1. If not, check to be

certain K1 has not been damaged. K1 should be available from Elecraft

since it is used in the XV144 which is still in production.

73,
Don W3FPR

On 9/25/2020 1:21 PM, k2qo wrote:
> Don and gang,
>
> I replaced Q3, U1 and the ADEX mixer. Results? Transmit works FB as
before
> and the RX still has no sensitivity. No change at all. I ran
through the
> setup related to the RX section and one thing stands out.
>
> Part VIII: RX Input Alignment
> Trimmer cap C1 has no effect on the AC voltage at the phone output
> connector. This is the same result I had before replacing the 3
parts.
>
> I think I may be down to signal tracing starting at the N
connector. But
> without a list of test points and voltages, this may be a
nonproductive
> PITA.
>
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Don Wilhelm

Re: XV222 RX is Dead, Need Advice

Yes, I have one - BUT
Elecraft has the schematics for all the transverters. Go to the manuals
page and open the Retired Products page.
Then select the XV Transverter Owner's manual and download it.
You will find in Appendix A the schematics for the XV50, XV144 and XV222.
If you have a printed copy of the Owner's manual for those transverters,
you will find the schematics for all of them in Appendix A.

The XV432 is a separate Owner's Manual. It has a different board layout
- the boards for the XV50, XV144 and XV222 are the same layout but the
components are different. See the board layout for each of them.

73,
Don W3FPR

On 9/25/2020 8:35 PM, [hidden email] wrote:

> Mark,
>
> Do you have a schematic for the XV222? I looked on their site and
> could not come up with one.
>
> 72
>
> Howard Kraus, K2UD
>
> -----------------------------------------
>
> From: "Don Wilhelm"
> To: "k2qo"
> Cc:
> Sent: Friday September 25 2020 2:44:03PM
> Subject: Re: [Elecraft] XV222 RX is Dead, Need Advice
>
> Mark,
>
> Sorry about your failed effort. There is little in the RX path other
> than Q3 and U1 that is not also used in TX.
>
> If you have equipment that can do signal tracing at 222MHz, just trace
> the signal path. There should be a significant increase in RF voltage
> at the output of Q3 and more at the output of U1. If not, check to be
> certain K1 has not been damaged. K1 should be available from Elecraft
> since it is used in the XV144 which is still in production.
>
> 73,
> Don W3FPR
>
> On 9/25/2020 1:21 PM, k2qo wrote:
> > Don and gang,
> >
> > I replaced Q3, U1 and the ADEX mixer. Results? Transmit works FB as
> before
> > and the RX still has no sensitivity. No change at all. I ran through the
> > setup related to the RX section and one thing stands out.
> >
> > Part VIII: RX Input Alignment
> > Trimmer cap C1 has no effect on the AC voltage at the phone output
> > connector. This is the same result I had before replacing the 3 parts.
> >
> > I think I may be down to signal tracing starting at the N connector. But
> > without a list of test points and voltages, this may be a nonproductive
> > PITA.
> >
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft/> Help:
> <http://mailman.qth.net/mailman/listinfo/elecraft<br>http://mailman.qth.net/mmfaq.htm/>
> Post: mailto:[hidden email]
>
> This list hosted by:
> <http://mailman.qth.net/mmfaq.htm<br>http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html/>
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