Your xmit output is pretty normal.? Some rigs can get 5-6W out on
CW, but 2-3W out on SSB is about it.
As I recall, 100uV at the antenna input should give an S-9
reading.? A 6 dB loss through the mixer sounds about right -- but
it has been a long time since I have done anything with my
QRPPlus.? And removing the SBL-1 mixer without destroying any pc
board traces is a challenge!? If you do decide to replace it, I
highly recommend that you install a socket.
In any event, your problem may well be elsewhere.
Larry -- W1HUE
On 5/10/2020 1:05 PM, wes Bolin wrote:
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I have been troubleshooting my deaf QRP+
transceiver.? It works on Transmit with 4W out on CW and 2W
out on SSB.? 100 uV on 20M gives about S-5 meter reading.? I
can barely hear 1 uV.
?
I thought it might be the First Mixer
SBL-1, but I was cautioned that it might not be because the
transmit would be bad also (mine isn¡¯t bad).? This is after I
pulled the board from the radio.? Well, I put it back in the
radio and
Measured signal levels with my TEK 100 MHz
scope and HP 8640B generator.
?
Here are signal levels at several points in
the circuit:
Antenna input was adjusted at 14.200 MHz
for 20 mV. (one cm pk-pk).
Measuring at C40 after the BPF was the same
20 mV.? This input to the SBL-1 Mixer.
Measured on C41 4 mV.? This is the Mixer
output and input to AMP. (-6 dB loss)
Measured Amp Output on C40 20 mV.?
?
Interesting is that with 20 mV at the
Antenna Input on 14.200 MHz ?I get about S-5 on the S-meter;
??????????????????????????????? with 20 mV
at the Antenna input on 50.000 Mhz?? I get about S-5 on the
S-meter. (same).
??????????????????????????????? And both
signals are same volume.
My questions are:
Is the SBL-1 good or bad?
If it is bad, How do I get it off the board
???
?
I need help to get my radio back in proper
operation.? Can anybody help me?? If I am on the wrong track,
then point me in the right direction?
?
Thanks, Wes
?
Sent from for Windows 10
?
