Search results

I'm really not supposed to be out in the heat working too long. 3 massive widow maker heart attacks, congestive heart failure, coronary artery disease, low ejection fraction (24%), ortho-static hypo-tension (not hyper-tension) and other health issues, but I just can't sit around while other...

Sorry, got tied up all day cleaning out our basement, we're having our foundation repaired.

Checked all the tubes in it today. It has 17JF6 tubes. 5 tested great at 75%, with no leakage seen while holding test button down. 3 tested at 25%, 2 of which held at 25% while holding down test button but the other one would start falling lower than 25% the longer I held the test button down...

Someone told me the 3CX400A would not handle much more than a 3 to 4 watt unmodulated carrier for input. From what I've read, it will handle from 9 to 15 watts unmodulated carrier input, claim being 12 watt unmodulated carrier input being the sweet spot. The guy I got it from ran a 30 watt...

The tubes helped some, but those cooked resistors being replaced helped tremendously. Still going over a few things on it before I test it out fully (Hammer on it). Checking out the 8 tube GTO now.

Ok, got the 8 tube GTO today. Everything looks great other than the center holes of both SO239's are wallered out big time. User got rid of due to not keying up anymore. He said he was talking on it and heard an arc around the rear corner and it smelt like electrical arc, then it wouldn't key...

No schematic, but I will take covers off this weekend and post some pics of the inside if you like.

Checked all the tubes: 5 tested around 75%, no drop down. 3 tested as 30%, with one dropping lower than 30% the longer the test button was held, guess this was the leaky one. Decided to just test the overheated 470 ohm resistors, replace the 4 cooked resistors and that yellow (cap? or...

You are looking at the last big amp Screwdriver (here in NC) ever built due to his health has left him unable to do it anymore. Turbo Smasher 1 tube - 3CX400A Max input key - 50w Max input swing - 50w Max output key - 500w Max output swing - 1700w Large squirrel fan

The 470 ohm resistors (some of which are circled in red across the tubes) come from pin 4 over to pin 8. From my understanding pin 4 is plate and pin 8 is G3 (I assume is ground 3). I also noticed a wire wound resistor on one of the top caps looks overheated. Would one or several of those 470...

Snag (Snaggletooth) passed away in 2021, he was one of the best in NC for years. Then Ray Phelps passed away a couple years ago. Now, Screwdriver is on his way out. Those were the 3 best around here. Basically only ones around here.

Mark 8 was made by Elkin (Ray Phelps). Yea, and running a constant 50 to 70 watts through it didn't help it none neither, lol....

Hi all, been away for a while and in the process I lost my login info. Thanks to CableGuy and AuduoShockWave for getting me back up. I truly appreciate you guys. Today we have a Mark 8 (8 Tube - 17DQ6B) amplifier on the desk. Yes, I'm now starting to do little repairs on these, although I don't...

Odd thing is, after I replaced the 7222 IC, then the volume came up slightly but transmit audio dropped out completely (still a carrier, but not modulation now) and the added talkback switch shuts receive down completely when flipped on (didn't do that before swapping out IC8). I figured the...

"I don't see C180 on that list, its a tantalum cap." , Brandon I see C180 location but there's nothing there. The schematic shows a tant at C180, the parts layout shows a tant at C180 but the cap list skips from C179 to C181 and doesn't list C180. Just a silkscreen marking for C180 but no tant...

Just got back on it today! Signal generator shows great sensitivity. Replaced: IC8 TA7222AP Replaced IC7 JRC4558 Q17 Q44 D16 D17 C80 C170 C172 C175 C179 C181 C182 C186 C187 C243 Receive volume still low in all modes, including PA mode with speaker plugged into PA jack. When I crank volume up...

I don't have 8v on either side of R233. I get 8v on the collector of Q17, but not on either end of R233. This is a different Q17, the old one had an HFE of 34, which I figured was too low, so I replaced it with another one with an HFE of 82.

I still do not have 8v on the RF gain control. Most I ever see on the RF gain control on this radio is 3.36v on any lead. R233 shows 3.36v on one end and 0v on the other, when I turn the RF gain down then the control has no voltage on any lead. Shows as a 1k ohm (in circuit). Replaced Q17 with...

Tested them in my TC1 tester. They showed about 640mv, I think

Yanked out Q17 and D16/D17. The transistor tested fine but with an HFE of 34. According to the datasheet the minimum HFE for a 1674 should be no less than 40. The two diodes tested fine as zeners.