Re: Noise Burst #bitx40

Allard PE1NWL
 

Yes, raduino_v1.27.7 fixes this problem.
Download it from https://github.com/amunters/bitx40
and install the related (minimal) mods (see instructions included).

73 Allard PE1NWL

On Tue, June 26, 2018 17:32, Jerry Gaffke via Groups.Io wrote:
Allard's fix to the Bitx40 carrier burst using a delay in the code is
described here:
    https://groups.io/g/BITX20/message/33756
    https://groups.io/g/BITX20/message/34189

There is also Raj's fix, strictly hardware, no code:
    https://groups.io/g/BITX20/message/33707
    https://groups.io/g/BITX20/message/33742

Those are all in the same thread.
The rest of the thread is worth browsing as well.

Jerry, KE7ER

On Tue, Jun 26, 2018 at 05:35 am, Michael Babineau wrote:


John et al : 

The RF burst on PTT closure, on the BITX40, has been addressed by Allard
(PE1NWL) in his Raduino Code.  

https://github.com/amunters/bitx40

His approach is to shut down the CLK output on the SI5351 for 50 mS on
PTT
closure and wait for things to settle before re-enabling it to allow
TX.  


There is also a simple hardware mod that can be used to reduce this
burst
from 50 mS to less than 20 mS so that the delay time can be reduced in
the
code.
The mod is to change C124 from 47uF to 4.7 uF. C124 is near Q12 (mic
input).  See message #29101 in this group for the original discussion
on
this. 

Cheers

Michael VE3WMB


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