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