• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • A Winner has been selected for the 2025 Radioddity Cyber Monday giveaway! Click Here to see who won!

6JB6 tube amp driving 10 pill hg 2879 bouncing swr

Jim5570091

297 Red Dog North Alabama
I Support WorldwideDX.com!
Oct 9, 2016
102
63
38
54
Guntersville AL
Strange swr behavior resolved.
Galaxy 2547 dead key .75 watts 4 tube 6jb6 driving x-force 10 pill.
Anytime I turned the dead key up past a 200 watt my swr would go from 1.2 steady to bouncing erratically all the way to 3. Some research pointed me toward a bad connection on my coax or arching. I` checked all my coax jumpers and feed line coax. Found no issues. A local old timer told me sometimes tube amps and solid state amps don't work well together. I took my 150 gray out of my mobile and used it to drive the 10 pill instead of the tube amp and bam the SWR is stable even all the way up to 800 watt dead key. I don't run it at a that high normally just testing. Has anyone experienced this before? Was it some kind of harmonics? Id like to understand what was happening. Its above my intellect. 73s cheers.
 

Don’t have a dummy load that will handle 1.5 KW. To find out. But just changing it from a tube type driver to a solid state stopped the bouncing fluctuation. My problem is solved but just trying to understand why a tube amp driving a solid state would cause that issue.
 
why a tube amp driving a solid state would cause that issue.
More than one way to make a tube amp unstable. Maco did it by feeding the output energy from the front panel to the rear through coax that had the shield braid not connected. Turned the shield into an antenna, feeding unwanted feedback into the input circuits. An amplifier that's on the verge of becoming unstable may behave perfectly on one antenna and try to oscillate on another antenna. The input circuit on the big amplifier has an influence on this. Just make sure the shield braid is soldered at each end of the coax jumper between the two amplifiers. Seen more than a couple of unstable setups caused by a poor shield connection inside one or both plugs of a coax jumper.

73
 

dxChat
Help Users
  • No one is chatting at the moment.