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Browning MKll 180
- Thread starter 238
- Start date
In theory, you put a SWR meter and coax jumper between the radio and the input jack of the amplifier.
Key the radio and amplifier, tune for best modulated power.
Now set the SWR meter's calibrate side and switch to read SWR.
The trimmer should reduce the reading, but won't get it very low in my experience.
The 180 was designed to use with tube-type radios that don't care too much about SWR when driving an amplifier.
This post shows a rebuild, including a small coil we add to the input trimmer cap. Serves to bring the input-side SWR better than the trimmer can do it alone.
[URL]https://www.worldwidedx.com/threads/browning-180-linear-back-from-the-funeral-pyre.238820/[/url]
That's the short version.
73
Key the radio and amplifier, tune for best modulated power.
Now set the SWR meter's calibrate side and switch to read SWR.
The trimmer should reduce the reading, but won't get it very low in my experience.
The 180 was designed to use with tube-type radios that don't care too much about SWR when driving an amplifier.
This post shows a rebuild, including a small coil we add to the input trimmer cap. Serves to bring the input-side SWR better than the trimmer can do it alone.
[URL]https://www.worldwidedx.com/threads/browning-180-linear-back-from-the-funeral-pyre.238820/[/url]
That's the short version.
73
Thanks a lot.I have had so much trouble finding info on a MKll 180. So i included pics of mine. The only things that look to be changed are the caps & it has 6KV6 tubes. All the resisters check ok. Could not check the two 1M resisters, i changed them. Can you buy new carbon resisters or are they all NOS? Thanks again. 238
Don't know how long those two 450-Volt filter caps will last. Original parts were rated at 500 Volts.
Years ago had trouble with using 450 Volt-rated parts, failing prematurely. Been using 500-Volt types ever since.
The input-tune trimmer might be bad, but the circuit they used is the real culprit.
I'll see if I can find some pics that will do a better job of explaining how we add the coil to that input circuit to get the input SWR below 2 to 1.
73
Years ago had trouble with using 450 Volt-rated parts, failing prematurely. Been using 500-Volt types ever since.
The input-tune trimmer might be bad, but the circuit they used is the real culprit.
I'll see if I can find some pics that will do a better job of explaining how we add the coil to that input circuit to get the input SWR below 2 to 1.
73