Re: Harmonics

Gordon Gibby <ggibby@...>

I barely know how to do this, but I uploaded the design document, and the zipped gerber files (which was happy with) to this github directory:

From: <> on behalf of Gordon Gibby <ggibby@...>
Sent: Sunday, August 12, 2018 11:15 PM
Subject: Re: [BITX20] Harmonics

I bit the bullet and submitted files to pcbway, for 10 printed circuit boards for external relays. 

While I was at it, I threw on a small bit of circuitry to give me a 3 terminal regulator and a backwards diode etc so if  I need to regulate a voltage for the receiver downwards, i can do that.  

printed circuit boards are amazing.     My local ARES group absolutely reduced their building time by at least 80% when I switched to giving them printed circuit boards that just have to be populated, rather than piont to point wiring.   My own building time went down similarly though i was much faster than beginners of course.

My plans are to get them this optional external relay set,  and also an optional daughter board with the popfix for those with v3 boards and maybe the AGC also..... but all that is in the future.   FIRST just to help them learn how to wire up the ubitx, with a bit of resistance in the speaker line if they have the IC amplifier.    ​  One step at a time!

I just got PAT working for the very first time on WINMOR....amazing....will give us winlink access from raspberries to uBitx transceivers.    


From: <> on behalf of Kees T <windy10605@...>
Sent: Sunday, August 12, 2018 10:53 PM
Subject: Re: [BITX20] Harmonics
On Sun, Aug 12, 2018 at 09:14 PM, Gordon Gibby wrote:

​Hi Keyes --- I wasn't following so not sure if this is for OUTPUT or as a preselector for the PA stage.   I don't know exactly how to read your PCB's but a few questions:


1.  I don't see the ground connection on the motherboard for the ground pins of the filter trays.

2.  Did you want to isolate the relay coils  input versus output?   I don't see inductors / capacitors to avoid energy getting AROUND the filters via the coils, the coil wiring and then out the other coil.



The ground pins on the filter trays are connected to the ground plane on the board and there are 3 grounds and the coax shields which return to uBITX ground. I'll also send the ground plane image. Does not have anything to avoid energy getting around the coils. Just basic LPF design, if/when the LPF is not used, both ends of that LPF are grounded. Relay contacts are redundant and bifurcated.

73 Kees K5BCQ

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