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Here is the part 25 u tube link. https://www.youtube.com/watch?v=-BpADwJMbOk

*Here, the soft start is wired up. Paralleled 25 ohm, 50 watt resistors used. Since there is a total of 125 uf for the filter cap assy, the step start has to be done very carefully, with the requisite

Thank you Peter and Chuck. I have discarded the Cera-Mite capacitor and ordered a .005 door-knob cap, with similar dimensions to the Cera-Mite, from Surplus sales. While waiting, I am finishing up the

On behalf of the estate of local KE5BR, available is an SPE Expert 1.5K amp in excellent condition. The amp was recently brought up to Series 2 specs with all factory updates being applied by Main

Same here, used exactly the same type to get more capacitance on 160m as a HT bypass capacitor It exploded after a few minutes. I assume those capacitors are not suitable for RF. 73 Peter, DJ7WW _____

Dear Dave, The 'PA makes a great project amp. I went with dual 3CPX800A7's and slammed together an outboard power supply. The power supply was way heavier than the RF head. I replaced the blocker with

Regarding replacing the plate blocking caps….if it ain’t broke, don’t fix it. I blew up one of those red plate blockers by Ceramite. It turns out that they are not rated for significant RF

I am doing some updating to my Alpha 76PA 3-tube amplifier.? I have switched the T/R relay to a pair of vacuum relays and changed the "relay" (AKA Send or PTT) request to send from 24 Volts to be a

I like to fit a C1 capacitor capable of withstanding the full EHT, and/or..... add an RFC between J1 and earth to protect the radio in case of flashover and C1 fail.

Jim, this worked great! I confirmed that the SWR reading on my meter was pretty close. I just used an antenna analyzer, and it read 1.8:1 with the slug all the way out. One of the oddities I noticed

I've seen reference to a "6M Kit" for the Clipperton V 2 Meter amplifier (uses a single 4CX250B). Anybody have any pix or drawings of this conversion? It seems to me that this amplifier was

Not even that, if you have a late-model radio with built-in SWR meter: simply turn your drive all the way down, like to 5 watts or less, then set your S-meter to read SWR. If the 572 filaments aren't

LEAVE the tubes in their sockets? when doing your input swr tests.? ?The tube's? grid to cathode C? is directly in parallel? with the C2? cap of each PI tuned input. (5.9 pf PER tube). If this

Hi Alex, Will do , thanks for the tip , there is something wrong. 73 Philip 9H1PA [email protected]> wrote:

I tackled the problem by taking the amp apart, removing the capacitor and the ball drive, cleaning and lubricating both. The front panel of the amp will have to be removed to get the ball drive out.

I asked about the input cap because a couple of years ago, a friend, VK6OX,had a problem with his dual GI7b 6m amp. It took forever, for VK6OX, VK6JX and myself to track down but it ended up being the

Hi Alex, Tnx for your reply. So the changes were not all at once. It was over a long time, one by one to try and find the cause Let me reply to your questions. *Have you hi pot tested the GS35b

Seems like you've changed too many things at once.? A few guesses off the top of my head. Have you hi pot tested the GS35b between cathode and grid? Are you able to swap the old tube back easily?

I'll take another look in there but looks like a b____ to get to it. I could have done this in my earlier years but eyesight is not what it used to be. How did you tackle the problem? 73, Garry

No bias diodes won’t affect the input tuning. ?On higher bands if the neutralization is off you’ll notice varying input swr with the load control, but you may still get drive with no foldback.