Dick,
Since your external counter fails to give the right frequency range with
BAND-, there is something more than the probe that is not right.
Look at the soldering of L31 and and the PLL crystal - reflow that
soldering as a first measure.
Check the value of RP2 - it should be 10k (last 3 digits 103).
Make certain D16 and D17 are not swapped. D16 should be an MV209 and
when viewed from the top looks about the same as a transistor. D17 is a
1SV149 which has a much thinner body. Check the orientation of D17
carefully too. It has 2 flat sides and the shorter flat side has
chamfered corners (or edges if you prefer). That shorter side is the
rounded side.
Because you have very close to the correct frequency with BAND+, I think
is happening.is the varactors are just fine when the reverse voltage is
high, but when the voltage is low, the capacity presented by the
varactors is too low. That could be caused by D16 and D17 swapped or
D17 in backwards, or not good connections to L31 and the crystal.
Since you may have a potential problem with the probe, check with your
external counter for both the PLL high and low frequencies. There is
nothing magic about the internal probe for that part of the procedure,
it is simply a check that the circuit is oscillating and the crystal and
varactors and L31 are behaving as expected. You have to get that
situation solved before the other tests will be meaningful. After you
have the correct frequencies on your external counter, if the internal
probe does not produce nearly the same frequencies, then you can
investigate the probe.
As for the LoBAtt message, that is likely coming from the plugging of
the 3 pin header P7 on the Control Board. The jumper should be in the
INT position (the 2 pins closest to the center of the board). If it is
plugged correctly, review the soldering on CB P7, R9, R19, and U3.
73,
Don W3FPR
On 4/9/2013 3:46 PM, Dickie M0AUW wrote:
Hi Don
I've removed RFC14 and re-tinned.
With an external frequency counter I'm getting a reading of 12099 at + and
between 1100.00 and 11.600 at -, but its turning over rapidly. If I finger
touch various components example relays 13 14 and 15 the signal will jump up
dramatically towards 15/16000, but I suppose that's to be expected.
I checked the internal counter probe all seems correct re connections and
I've re-soldered TP3, but any slight movement on the probe and the signal
does vary but still around the 00.467 to 00.500 mark.
The only other abnormality is that on switch on I get a "Lo Batt" for a
couple of seconds, puzzling as I'm using a 12v 5amp PSU, would this cause
any issues?
By chance I do have some spare 2N2222 transistors so if all else fails I can
replace Q9 and 10.
73s - Dick M0AUW
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