Thanks to all for the information. I have decided to open up the Hercules, check the individual power supply voltages (and hopefully not have to get into the 9420 to adjust them), measure the individ
Ken.... With the amp turned on its side, and with the front panel at the left, looking at the amplifier boards: Bias board pots R14 controls upper left amp R10 controls upper right R2 for lower left
Thanks again Phil. The PA module idling currents were not high. With the amp not keyed they were all zero. And keyed with no drive, they were all around 0.4 to 0.5 Amp. I now have them adjusted to as
Ken... I agree completely. While you've got it opened, though, you might consider changing out U5 on the distrib board. 73 Phil VFO Stabilizers and PEP adapters for wattmeters...Check out http://home
I only see a U1, U2 and U3, all LM358N. There is a non-zero DC input on the + input of U3, with the amp on and not keyed. So I think that the DC offset may be coming from U1 or U2. I would replace th
Ken... Your meter is indicating a static current flow that, by measurement, you don't have. That means one of the meter amplifiers on the distribution board (or U5) is leaking. You can learn which on
Hi Phil Yes Where is U5? Ken N6KB _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec
If your Herc II has one, U5 should be on the distribution board, as I mentioned. Some have only the LM301 chips U1-U4 for the Ic meter amps. Phil K4DPK VFO Stabilizers and PEP adapters for wattmeters
Mine only has U1, U2 and U3, all LM358. I wonder how many versions of this board there are? Ken N6KB _______________________________________________ TenTec mailing list TenTec@contesting.com http://