Search results

About 40 watts dead key. 3 watts out of radio. Cobra 200. 238

Well i put it back together with out a resistor. It does have some effect now. The only thing i changed was the coax, put 316 in it, grounded at both ends. Using a Drake W4 between radio & amp it shows 1 watt in reverse. Going try a resistor in line later after i run it a little. 238

I had to change the pin # because i put the wrong # in the first post.

I hope your 300A is working ok. You did a great job on that amp. I have run one before an it did a great job. 238

Dmans said in the rebuild of his 300A he used RG313. I have RG178 & RG316, but can not find RG313. I was wondering if that was a misprint? I can not find any thing on RG313. 238

Changed the coax out to 316 grounded at both ends. When they changed it to all finals they removed the driver tune. You have the input match still there. It is a 304m with the coil soldered across the legs. One wire, off the coil, goes to the relay the other to pin # 3 & 11. Pin 3 & 11 are...

So it is best to use a carbon- composition or a carbon film in the input like Maco did? Thanks 238

It has 6lb6 tubes. The coax has been grounded on both ends, but it is old coax. I will change it to 316 coax like i did my others. Then i will try the swr meter in between the radio & amp. Thanks 238

I bought this amp 7 years ago, ran it some. It had been converted to all finals. 6lb6 Decided i needed to overhaul it. The input never had any effect on it. I added a 100pf across the legs no different. I have put new caps & diodes in it. No sure how you figure out what to do with the input. 238

Put a 22 ohm resistor in the input an every thing seems to be working ok. I must be looking at this backwards. The 22 ohm let the key go down as the 180 ohm made it go up. 238

Well changed the grid resistor back to the 3 ohm resistor. Dead key 80 to 100, swings to 150 to 180. The other 2 tuber i got has a 22 ohm x 2w for the input resistor. I put a 180 ohm in this one, thing i will put a 22 ohm in it an see if that changes the dead key. 238

I got my Maco Super 75 back together with new caps. Bias set at -103 vdc. Works goodbut seem it keys to high 80 watts swings to 150 on my Swan meter. Had 5 ohm x 5 watt grid resister changed to 3.9k. Has 357 volts at the tube keyed. Changed the input resister to a 180 ohm, with a 270pf across...

That was KJ4CYH's amp, on another post that had the tube turning red.It was a Brute 2 tuber. 238

The one in the Super 75, 2 M2057, appears to be 47 ohm it checks at 58 ohm. How would you know if you need to change the value? 238

The pic is a before pic. The coax has been replaced with 316 coax & grounded at both ends. The 2 resisters going to pin 3&11 have been changed too 100 ohm x 2 watt. The sch, from nomad, is for a Maco/ Brute 75, 1 M2057, so would the 180 ohm be correct for the Super 75 with 2 M2057? As Chris...

The sch is for a Maco/ Brute 75, 1 M2057, so would the 180 ohm be correct for the Super 75 with 2 M2057? 238

Recon needs to put a good picture of the inside of his amp so you can see how it is done. His looks odd as compared to mine. 238

r This was supposed to go on the other post. 238

This one has 2 M2057 in it. The disc cap is 270pf. I put a 100 ohm resisters too pin 3 & 11 on each tube.

Trying to find out the size of the resistor going from the input too the tube. Can not tell by the color bands. On Nomads sch not sure if it 18 ohm or 180. The one in mine reads 77 ohm, but guessing at the band colors it looks like 47. 238