Bill, Interesting. Same issue with the Drake 1A. Sensitivity is affected by the quality of the antenna trimmer capacitor bonding to chassis ground.
Paul, W9AC ----- Original Message ----- From: Bill & Becky To: drakelist@zerobeat.net Sent: Saturday, September 01, 2012 7:44 PM Subject: [Drakelist] R4C Interesting Find My R4C seemed a bit poor in the sensitivity department so I had an idea to improve it. I aligned the R4C pretty well but it didn't seem very lively. So with the bottom chassis visible I took my screw driver and loosened/ tightend each screw twice on each side of the 4 rows of trimmer bracket ground. Wow.....what a difference in sensitivity mainly 160-20M and in between. I estimate a 8-10 dB of more gain. I learned this method of re-establishing grounds from a metallurgist(sp)ham neighbor who showed me what happens to two surfaces create a fine film a lose bonding with time. If the two metals are much different the faster the degradation. Your mileage may vary. I recommend all accessible screws and nuts.......it can cure some pretty obscure problems and takes less than 15 minutes. I had to recalibrate the S-meter because of the gain change. It should work on R4any receiver........or any old boatanchor. Bill KB9IV ------------------------------------------------------------------------------ _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
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