Re: Harmonic performance - SSB vs CW

Timothy Fidler
 

before you rush in with the Tx Rx relay which does a lot of work sugggest you look at this


Adwww.digikey.co.nz/


the URL is humungous hence you need to look it up.

It shows a circuit for a source switching into one of two loads .. NOT what the Tcvr requires but SImilar

This Allison alluded to this circuit the one with the two diodes and said that POWER diodes can be used a five Watt level .  am not sure if the isol to the Rx will be enough. BUT if i does work it will be state of the art and cheaper than a click clack relay  RF IO switch only. 

There are plenty of two amp and more schottky diodes around for cheap as in 26 US cents or so. As I say see what Allison has in terms of proven design or perhaps just leave lands on the board so a user can surface mount TH parts or put in a relay as he prefers. 

SS switching of the RF for tx rx would be a big plus if it worked and would make the PCB very popular.


 I also have a proven UK speech compressor design schematic  only using a high brightness yellow diode etc total parts cost say around 8 AUD.  There is a VK3 hawking around his own "you beaut design" whereas this one is superior and  has variable gain and has been around for TWENTY years. 

 

Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885, 
Telephone Whangarei   022  691 8405
e: Engstr@...



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Mon, 06 Aug 2018 19:01:10 -0700
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Re: [BITX20] Harmonic performance - SSB vs CW


Thanks Tim.

I will Implement the diode switching to reduce IO ports required... or even go i2c bus? hmm...

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