Hi all,
Thanks for giving some ideas!
I checked the resistors on the bottom of the ssb board, they are all
correct. I must say that trying to identify parts on the top of the
board is a real challenge, its so stuffed that its almost impossible!
Don, I redid the output amperage at 10 watts:
80 - 2.68
40 - 2.72
30 - 2.28
20 - 1.96
17 - 2.42
15 - 2.50
12 - 2.24
10 - 2.16
At 10 watts on 40, the voltage on rx is 13.5 on tx its 12.9.
The group is right, I did not notice the power output on lower than 17m
(which is 15 watts). On 15 through 10, highest output is 13.3 watts.
Do I still need to investigate the 40m current usage?
Do I need to replace the 3 resistors and jumper that I pulled out to
eliminate the noise blanker module from the mix of things to
investigate? I should have done one module and waited to know it worked
before doing a second one!
Neal
On Feb 21, 2005, at 5:37 PM, W3FPR - Don Wilhelm wrote:
Neal,
There may be nothing wrong with 40 meters after all - I had missed the
point
that you were setting the Power control to absolute max. What is your
power
supply voltage? 13.8 volts is typical (13.6 on the display), and lower
power supply voltages will result in increased current draw. What is
the
voltage when you are seeing a current of 3 amps or greater?
I don't have a straightforward answer here. Can it be that your
Carrier
Balance is not correctly set and you are really generating more RF
drive
with SSB than with CW?
It is not really a fair comparison to compare current draw from band
to band
with the Power control set all the way clockwise. Set it to 10 watts
and
check the current drawn for each band and both CW and SSB modes.
Actually SSB mode should draw little current without audio if the
carrier is
balanced because there should be little or no RF output.
73,
Don W3FPR
-----Original Message-----
Hi Don and all,
I have spent the afternoon looking for where I could have made a
mistake on the 40m LPF circuit. I didn't find any obvious ones, the
toroids came from 'The guy de Toroids' but I counted them all anyway,
and they are (luckily!) correct. Same for capacitors. Did the run of
voltage checks and didn't notice anything really wrong.
On cw, cranking the output knob to the max, the display readings for
current are
80 3.22
40 3.36
30 2.84
20 2.38
17 3.08
15 2.84
12 2.62
10 2.42
Output reads over 15 watts in all cases, usually abt 15.2. This reads
pretty much the same with or without the SSB module installed.
I take it from your comments that the fact that 40m is the highest cw
reading, its indicative of something wrong. Looked at LPF and BPF
areas. What should I expect on the amp readings, 2.35 on 40 and a
gradual increase as I go towards 10m?
I could reinstall the resistors and jumper and take out the noise
blanker module as thats something put in yesterday, I take it that I
need to do that if I want to test without it?
I have boosted cal cur to 4.0 and still can get hi cur signal with
output fully counterclockwise on both usb and lsb. I have been very
happy working cw all week as it is (set the cal cur to 3.5 and it
hasn't tripped yet).
Any more ideas to look at?
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