I have been trying to reduce the 2nd and 3rd harmonics leaving the BITX40v3 for days and I just added the 100pf capacitor across L7 LPF coil and I will say it has solved all of my problems with higher than ideal harmonics. It is mentioned in the WAX articles along with the opposing diodes on the base of Q13. `My results on the spectrum analyzer was dramatic reducing all spurious signals well below 50 dbm. I have added the diodes as well as the100pf cap and recommend it for all BITX users.?
On Thu, Jul 27, 2017 at 2:10 PM, Jerry Gaffke via Groups.Io
<jgaffke@...> wrote:
1n4148's seem to work fine.
1n914's likely do as well, the Vishay datasheets look about the same.
Could be Vishay ships the exact same part.
The 1n914 is older, other manufacturers might spec a lower max forward current or something.?
"Back to back" and "front to tail" are both a ambiguous.
I suppose you could look at one of the drawings/photos previously posted.
? ??
Jerry
On Thu, Jul 27, 2017 at 01:44 pm, Mr Sheesh wrote:
I had been wondering if we were talking PIN diodes or what, 4148s
