Neal, Just an additional note - I usually adjust the SSB Carrier balance by looking at the RF output (with no audio signal) with my 'scope - I adjust the carrier balance for minimum power output (compromising if necessary between USB and LSB). You should find the proper point near the mid-point setting of the carrier balance pot. If it is not near the midpoint, look for some component misplaced or improper soldering.
73, Don W3FPR > -----Original Message----- > Taking things in reverse order - go ahead and put the Noise Blanker itself > back in rather than the 6 dB pad resistors. It will only affect > the receive > path and not the Transmit path. > > OK - your current draw at a constant 10 Watts output looks just > fine to me. > It is a bit unusual that your minimum current draw for 10 watts > out is at 20 > meters - usually that will occur at 40 or 30 meters - but this > does not look > like a real problem to me (actually it indicates better efficiency than > normal on the higher bands). > > > so now that still leaves us with the original problem of excessive current > draw in SSB mode. Actually something is 'fishy' here, because an > SSB signal > with no audio will result in very little output power (and quite > low current > draw). So my thinking now is that you do not have the SSB balance set > properly - or there is something incorrect on the KSB2 board. I > know it is > difficult to do, but do look again - particularly at the balanced > modulator > and those things shown around it in the schematic. It does now seem that > your problems are coming from the KSB2. Just as a wild guess I must ask - > did you remove C167 from the RF board when installing the KSB2? > If you fail > to remove it, that alone could explain the conditions you are seeing. > > 73, > Don W3FPR > > > > > -----Original Message----- > > > > 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? > > >> > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
