any tips for debugging RFI issue? #ubitx-help

Mike KK7ER
 

Our uBITX v3 behaves just fine when transmitting into a dummy load.  But when transmitting into an end fed wire with SWR 1:1 it misbehaves.  When transmitting CW, the uBITX gets stuck in transmit for a few seconds after I release the key.  When pushing the PTT switch, it also sticks in transmit but the menu also comes up on the display.  If the internal wiring was too long, I would expect the issue to show up with both dummy load and antenna.  I suspected the counterpoise (coax shield) was bringing RF back into the radio.  A number of sources seemed to suggest an "air choke" so I wound 20 feet of coax tightly around a plastic bottle and placed that between the antenna and feedline/coax but it made no difference.  Any tips from the antenna gurus here would be very much appreciated.

73 Mike KK7ER

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