I have a Radio Shack HTX-10 10 meter xcvr that does not transmit on
USB or LSB but works fine (at least into a dummy load) on AM and FM
and its receiver also work fine.. Any ideas what I may be doing wrong?
I would assume (possibly a fatal error on my part) that the transistor
finals are not blown, otherwise I would not have power on AM - FM.
Right? Any suggestion would be appreciated.

John WA9WHD Lutz, FL

When you say it "works fine" into a dummy load, do you mean you can see power output on AM & FM, or that you've listened with another rcvr to know you're actually modulating the rig?

The reason I ask is that in SSB, something as simple as a faulty microphone can reduce your power out to zero, but on AM or FM you'd see the carrier power output and assume it "works fine".

Check it out!

The Man in the Maze
QRU at Baboquivari Peak, AZ

On May 11, 7:59 pm, Iitoi wrote:
WA9WHD;569905 Wrote:

I have a Radio Shack HTX-10 10 meter xcvr that does not transmit on
USB or LSB but works fine (at least into a dummy load) on AM and FM
and its receiver also work fine.. Any ideas what I may be doing wrong?
I would assume (possibly a fatal error on my part) that the transistor
finals are not blown, otherwise I would not have power on AM - FM.
Right? Any suggestion would be appreciated.

John WA9WHD Lutz, FL

When you say it "works fine" into a dummy load, do you mean you can see
power output on AM & FM, or that you've listened with another rcvr to
know you're actually modulating the rig?

The reason I ask is that in SSB, something as simple as a faulty
microphone can reduce your power out to zero, but on AM or FM you'd see
the carrier power output and assume it "works fine".

Check it out!

The Man in the Maze
QRU at Baboquivari Peak, AZ

--
Iitoi

Thanks for your reply - I check it with a Drake W-4 watt meter. I have
not heard my voice signal on another receiver - so it might still be
the microphone as you suggest as a potential source of the problem.
When I press the mic key in AM-FM, it registers power on the watt
meter and the TX and Signal Bar displays show. When I transmit on SSB
- no power, no signal bar display increase but the TX display shows.
It is possible that the microphone element is bad even though the
microphone switch still apprears to work? Unfortunately, I don't know
of another ham in the area with a HTX-10 where I could check the radio
and microphone against another HTX-10. Thanks for any additional
advice on this. 73 John WA9WHD

WA9WHD wrote:
On May 11, 7:59 pm, Iitoi wrote:
WA9WHD;569905 Wrote:

I have a Radio Shack HTX-10 10 meter xcvr that does not transmit on
USB or LSB but works fine (at least into a dummy load) on AM and FM
and its receiver also work fine.. Any ideas what I may be doing wrong?
I would assume (possibly a fatal error on my part) that the transistor
finals are not blown, otherwise I would not have power on AM - FM.
Right? Any suggestion would be appreciated.

John WA9WHD Lutz, FL

When you say it "works fine" into a dummy load, do you mean you can see
power output on AM & FM, or that you've listened with another rcvr to
know you're actually modulating the rig?

The reason I ask is that in SSB, something as simple as a faulty
microphone can reduce your power out to zero, but on AM or FM you'd see
the carrier power output and assume it "works fine".

Check it out!

The Man in the Maze
QRU at Baboquivari Peak, AZ

--
Iitoi

Thanks for your reply - I check it with a Drake W-4 watt meter. I have
not heard my voice signal on another receiver - so it might still be
the microphone as you suggest as a potential source of the problem.
When I press the mic key in AM-FM, it registers power on the watt
meter and the TX and Signal Bar displays show. When I transmit on SSB
- no power, no signal bar display increase but the TX display shows.
It is possible that the microphone element is bad even though the
microphone switch still apprears to work? Unfortunately, I don't know
of another ham in the area with a HTX-10 where I could check the radio
and microphone against another HTX-10. Thanks for any additional
advice on this. 73 John WA9WHD


Hi John,

The key is the full name of the mode, "Single Sideband Suppressed Carrier".
No carrier = no output until you add modulation. With AM or FM, you would
have output whenever the PTT is enabled, regardless of any modulation. The
user manual says the microphone is an electret condenser type. A continuity
check of the mic element itself would show open. The manual doesn't
indicate there's any battery inside the microphone to power an internal
preamplifier. However, if there IS one inside, the transceiver should be
supplying a low DC voltage from the mic jack. On the other hand, do you by
chance have the microphone gain turned down?

73,
Bryan WA7PRC

On May 13, 12:04 am, "Bryan" wrote:
WA9WHD wrote:
On May 11, 7:59 pm, Iitoi wrote:
WA9WHD;569905 Wrote:

I have a Radio Shack HTX-10 10 meter xcvr that does not transmit on
USB or LSB but works fine (at least into a dummy load) on AM and FM
and its receiver also work fine.. Any ideas what I may be doing wrong?
I would assume (possibly a fatal error on my part) that the transistor
finals are not blown, otherwise I would not have power on AM - FM.
Right? Any suggestion would be appreciated.

John WA9WHD Lutz, FL

When you say it "works fine" into a dummy load, do you mean you can see
power output on AM & FM, or that you've listened with another rcvr to
know you're actually modulating the rig?

The reason I ask is that in SSB, something as simple as a faulty
microphone can reduce your power out to zero, but on AM or FM you'd see
the carrier power output and assume it "works fine".

Check it out!

The Man in the Maze
QRU at Baboquivari Peak, AZ

--
Iitoi

Thanks for your reply - I check it with a Drake W-4 watt meter. I have
not heard my voice signal on another receiver - so it might still be
the microphone as you suggest as a potential source of the problem.
When I press the mic key in AM-FM, it registers power on the watt
meter and the TX and Signal Bar displays show. When I transmit on SSB
- no power, no signal bar display increase but the TX display shows.
It is possible that the microphone element is bad even though the
microphone switch still apprears to work? Unfortunately, I don't know
of another ham in the area with a HTX-10 where I could check the radio
and microphone against another HTX-10. Thanks for any additional
advice on this. 73 John WA9WHD

Hi John,

The key is the full name of the mode, "Single Sideband Suppressed Carrier".
No carrier = no output until you add modulation. With AM or FM, you would
have output whenever the PTT is enabled, regardless of any modulation. The
user manual says the microphone is an electret condenser type. A continuity
check of the mic element itself would show open. The manual doesn't
indicate there's any battery inside the microphone to power an internal
preamplifier. However, if there IS one inside, the transceiver should be
supplying a low DC voltage from the mic jack. On the other hand, do you by
chance have the microphone gain turned down?

73,
Bryan WA7PRC- Hide quoted text -

- Show quoted text -

Hi Bryan:

Will check out the continuity of the microphone and see if a battery
is inside. The mic gain is full clockwise (turned up) but there is no
difference in output where it is set.

Thanks for the tips. will give it a try.

Best.

John WA9WHD

Based on the fact that you show power output on AM and FM, you have proved most of the transmitter circuitry is good, almost certainly everything northwest and south of the balanced mixer on your schematic. You have also proved the PTT control circuitry.

Examine the schematic and do some elementary signal tracing east of the balanced mixer. I'm betting on the microphone itself, or the signal processing just west of it on your schematic.

The Man in the Maze
QRL at Baboquivari Peak, AZ

"WA9WHD" wrote in message
s.com...
On May 11, 7:59 pm, Iitoi wrote:
WA9WHD;569905 Wrote:

I have a Radio Shack HTX-10 10 meter xcvr that does not transmit on
USB or LSB but works fine (at least into a dummy load) on AM and FM
and its receiver also work fine.. Any ideas what I may be doing wrong?
I would assume (possibly a fatal error on my part) that the transistor
finals are not blown, otherwise I would not have power on AM - FM.
Right? Any suggestion would be appreciated.

John WA9WHD Lutz, FL

When you say it "works fine" into a dummy load, do you mean you can see
power output on AM & FM, or that you've listened with another rcvr to
know you're actually modulating the rig?

The reason I ask is that in SSB, something as simple as a faulty
microphone can reduce your power out to zero, but on AM or FM you'd see
the carrier power output and assume it "works fine".

Check it out!

The Man in the Maze
QRU at Baboquivari Peak, AZ

--
Iitoi

Thanks for your reply - I check it with a Drake W-4 watt meter. I have
not heard my voice signal on another receiver - so it might still be
the microphone as you suggest as a potential source of the problem.
When I press the mic key in AM-FM, it registers power on the watt
meter and the TX and Signal Bar displays show. When I transmit on SSB
- no power, no signal bar display increase but the TX display shows.
It is possible that the microphone element is bad even though the
microphone switch still apprears to work? Unfortunately, I don't know
of another ham in the area with a HTX-10 where I could check the radio
and microphone against another HTX-10. Thanks for any additional
advice on this. 73 John WA9WHD

You have little to none in troubleshooting skills!
You cant find another RCVR to listen to it on?
On SSB you COULD use a simple diode and a earphone to see if you can hear
SOME RF....
You COULD touch the audio in pin on the mic connector with your finger and
see if the power goes up....
You COULD get some SIMPLE test gear.....
That radio is So damn simple you dont need a schematic......
Your WA9 call must be a vanity call, no way in hell you got that way back
when and still dont know **** about transmitters...


*THIS* is what happens when HAMS get their license from the Gordon West
school of fraud. If you were a REAL Amateur radio operator not only could
you troubleshoot this, but have it working in minutes.
Congrats....appliance operator....

On May 14, 12:35 am, "Porgy Tirebiter" wrote:
"WA9WHD" wrote in message

s.com...





On May 11, 7:59 pm, Iitoi wrote:
WA9WHD;569905 Wrote:

I have a Radio Shack HTX-10 10 meter xcvr that does not transmit on
USB or LSB but works fine (at least into a dummy load) on AM and FM
and its receiver also work fine.. Any ideas what I may be doing wrong?
I would assume (possibly a fatal error on my part) that the transistor
finals are not blown, otherwise I would not have power on AM - FM.
Right? Any suggestion would be appreciated.

John WA9WHD Lutz, FL

When you say it "works fine" into a dummy load, do you mean you can see
power output on AM & FM, or that you've listened with another rcvr to
know you're actually modulating the rig?

The reason I ask is that in SSB, something as simple as a faulty
microphone can reduce your power out to zero, but on AM or FM you'd see
the carrier power output and assume it "works fine".

Check it out!

The Man in the Maze
QRU at Baboquivari Peak, AZ

--
Iitoi

Thanks for your reply - I check it with a Drake W-4 watt meter. I have
not heard my voice signal on another receiver - so it might still be
the microphone as you suggest as a potential source of the problem.
When I press the mic key in AM-FM, it registers power on the watt
meter and the TX and Signal Bar displays show. When I transmit on SSB
- no power, no signal bar display increase but the TX display shows.
It is possible that the microphone element is bad even though the
microphone switch still apprears to work? Unfortunately, I don't know
of another ham in the area with a HTX-10 where I could check the radio
and microphone against another HTX-10. Thanks for any additional
advice on this. 73 John WA9WHD

You have little to none in troubleshooting skills!
You cant find another RCVR to listen to it on?
On SSB you COULD use a simple diode and a earphone to see if you can hear
SOME RF....
You COULD touch the audio in pin on the mic connector with your finger and
see if the power goes up....
You COULD get some SIMPLE test gear.....
That radio is So damn simple you dont need a schematic......
Your WA9 call must be a vanity call, no way in hell you got that way back
when and still dont know **** about transmitters...

*THIS* is what happens when HAMS get their license from the Gordon West
school of fraud. If you were a REAL Amateur radio operator not only could
you troubleshoot this, but have it working in minutes.
Congrats....appliance operator....- Hide quoted text -

- Show quoted text -

Thanks for your constructive ideas.

On 14 May 2007 05:00:11 -0700, WA9WHD wrote:
On May 14, 12:35 am, "Porgy Tirebiter" wrote:

*THIS* is what happens when HAMS get their license from the Gordon West
school of fraud. If you were a REAL Amateur radio operator not only could
you troubleshoot this, but have it working in minutes.
Congrats....appliance operator....- Hide quoted text -

- Show quoted text -

Thanks for your constructive ideas.

He's just demonstrated that he's a lid himself. I guess that life is
too stressful for him in Irvine, CA.

Good luck with your vintage rig.