Plate Choke opens w/ a bang while tuning 20m

[Naysayer]

Wire looks like 24-26? Reviewing my options: re-wind or get another. Uncertain what choke goes with 2 4cx300 tubes. When the attached picture is enlarged, a bulbous glob of copper is evident on each end of the wire break. Like a melted fuse.
Choke went during 200w cw tuning with 4w drive. 20M continues to be problematic. 10 working better than 20 after more adjustments to the Input inductors but it's slow going. Have a better switch with more positions. If I can squeeze a 2" small coil stock inside, I'll try that for the higher bands. I need a better inductance meter or other piece of equipment before I put more time into the input.

Antennas working great! The new mast-mount 2:1 coax switch and 400 coax made a big difference!

neil NYC

 

[Captain Kilowatt]

Sounds like you have a resonance in that choke somewhere on 20m. If the plate choke does indeed have a resonance on 20m, or any other frequency you use, the choke will have to be rewound slightly different to move that resonance point outside the band.

 

[Naysayer]

Thank you. Sounds like a good focus. I already began rebuilding the Input section and re-wound another choke. I'm waiting on some parts including a better LCR meter. I went with M-162 LCR kit ($40) only thru-hole components need be assembled. 40/80 no problem but I cannot see where I am below 3uH for the parallel resonance input a'la Pride.

Nomad, thank you. Hold on that choke if it's not too late. I have several ceramic forms and I don't want to ruin fine while I'm still poking around ruling stuff-out. The cheaper LCR I had was not reliable below 3uH. Poking around however got me to a 11position tapped 3uH coil (416T). I'll find that sweet spot sooner or later, lol.

Had to walk away for awhile but I was able to make a plan and order parts and meter so............. like Arnold says, I'll be back.

neil NYC

 

[Naysayer]

When it rains it pours. Thank you Nomad, came today in the USPS.