Re: Damage to SMT version bitx40 from nearby transmitter

 

Thomas,

At pin 12 of K1 relay solder 2 4148 diodes in parallel but in opposite polarity. This will limit the receiver from getting high RF voltage.

Also if you cut the track between K1 pin 12 and K2 pin 14 and insert a 12v 60 or 40 ma miniature incandescent bulb it would be better. This is common protection method in commercial transceivers and amps. This track seems to be on the component side.

https://www.radioshack.com/products/radioshack-12v-microlamps-2-pack

cheaper still!

http://www.ebay.com/itm/20pcs-Miniature-lamp-3mm-12v-Indicator-Bulb-Bombilla-Incandescent-Filament-CA-/142126593160

73 Raj vu2zap


At 17/12/2016, you wrote:
 

How likely is this to happen? Bitx40 connected to 40M resonant antenna perpendicular to another antenna with a 100W transceiver running a Winlink gateway.

I fully expect front-end overload and nasty noises, but will the coupling cause actual damage> I would like to leave the bitx40 running but volume minimized to lessen drift during warm-up period.

Currently I leave it running but antenna dis-connected, but it is only a matter to time until my feeble brain forgets.

Thomas W Noel
KF7RSF

Join BITX20@groups.io to automatically receive all group messages.