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Help with BitX40 Ver 2 #bitx40help


AGØH
 

I have a completed BITX40 - Ver.1.  I’ve decided to upgrade to Ver.2.  The instructions call for the center of a piece of coax to be attached to pin 6 of T4.  When I look at that coil, I see the wire of the coil going into what looks like a black connector.  I want to solder the center of the coax to that point but I believe the wire on the coil is covered with a red lacquer.  Can someone please give me some advice as to what the best procedure is to complete the soldered connection?  IOW does the black looking connector come unplugged from the board or do I just try to scrape off a small amount of lacquer and then complete the soldered connection?    73, Keith AGØH


Jerry Gaffke
 

I assume you are looking at Allard's mod to the Bitx40 for driving the BFO from the si5351 instead of the analog BFO:
  https://github.com/amunters/bitx40-raduino-v2/blob/master/digital%20BFO%20mod.png

The photos show that Allard had an early run of the Bitx40.
Later runs had a plastic carrier under the transformers to add mechanical support.

If I were you, I'd probably solder the coax center to T4 pin 6 on the bottom of the board,
braid gets soldered to the nearby ground plane of which there is plenty.
Alternately, you could solder to that same node where it enters C106, at the other end of the trace from T4 pin 6.
Or could chip away at that black plastic support under T4 to make the pin 6 pad visible, solder to the pad as Allard has done.
Or could scrape a bit of the red enamel from the T4 pin 6 wire, as you suggested.

Jerry, KE7ER


On Thu, Apr 4, 2019 at 05:43 PM, AGØH wrote:
I have a completed BITX40 - Ver.1.  I’ve decided to upgrade to Ver.2.  The instructions call for the center of a piece of coax to be attached to pin 6 of T4.  When I look at that coil, I see the wire of the coil going into what looks like a black connector.  I want to solder the center of the coax to that point but I believe the wire on the coil is covered with a red lacquer.  Can someone please give me some advice as to what the best procedure is to complete the soldered connection?  IOW does the black looking connector come unplugged from the board or do I just try to scrape off a small amount of lacquer and then complete the soldered connection?    73, Keith AGØH


AGØH
 

Thanks Jerry.  My original thought was to follow the trace and solder to the end of the cap but wondered about the possibility of 'stray' rf coming from that trace.  I’ll take the easiest route 😉 and keep my fingers crossed.
thanks again for the quick reply es 73, Keith AGØH