Batboard

I have an excellent condition Spectra D44KXA7JA5BK. I was able to add conductive pen ink to the VCO and everything works to 440.00. Both RX and TX VCO lock good. The receive however, isn't as tight as I would like. Around 440.00 monitor is showing about 1.1 uv. At 442.00, goes to .75uv and at 446 is about .5uv. Is there a way to adjust the sensitivity? This radio works perfectly otherwise in the UHF HAM band.

Thanks,
Mike

The receiver filter is one piece and not tunable.

Some have screwed around with the conductive stuff but it has problems.... NOT RECOMMENDED.

radiocat37 wrote:I have an excellent condition Spectra D44KXA7JA5BK. I was able to add conductive pen ink to the VCO and everything works to 440.00. Both RX and TX VCO lock good. The receive however, isn't as tight as I would like. Around 440.00 monitor is showing about 1.1 uv. At 442.00, goes to .75uv and at 446 is about .5uv. Is there a way to adjust the sensitivity? This radio works perfectly otherwise in the UHF HAM band.

Thanks,
Mike

I have used the brute force method and just blobbed solder onto the ceramic discs to lower their tuning point. It may take a few tries, but you can get it better than what it is by leaving the front end alone.

Jim

Jim202 wrote:I have used the brute force method and just blobbed solder onto the ceramic discs to lower their tuning point. It may take a few tries, but you can get it better than what it is by leaving the front end alone.

Jim

Another bad idea, the coating/plating on the receiver resonator is VERY thin, and heat will lift the plating.