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ZS1AGX > QRP 13.03.06 11:15l 25 Lines 854 Bytes #999 (0) @ WW
BID : 660126ZS1AGX
Read: GUEST HA1SE DL9NDQ DG9NBR
Subj: 7+ 6MTAMTX .BMP SCHEMATIC INFO
Path: DB0FHN<DB0FOR<DB0MRW<DK0WUE<7M3TJZ<HS1LMV<TU5EX<ZS0MEE<ZS0BEL<ZS0STB
Sent: 060223/2351Z @:ZS0STB.TBG.WCP.ZAF.AF #:38007 [Satgat] FBB7.00g25
From: ZS1AGX@ZS0STB.TBG.WCP.ZAF.AF
To : QRP@WW
common collector schematic 2N3866 for AM six ( a .bmp file)
You don't see many common collector circuits. They have lower gain than
common emitter configuration.
Common collector circuits have to be tamed; there should be low
capacitance between the drive winding and the base winding.
The 180 ohm and 330pf combination help for stability.
Common collector circuits are good for cheaper transistor packages so the
tab (collector) can be bolted down. My common collector has the 2N3866
soldered into a hole through the PCB (remember the collector is +ve!!)
Here the LM358 can provide 20mA drive with +/- 5v audio for AM.
But can the circuit be made to work as a CW receiver too? It there audio
(beat) on the secondary of the "modulation" transformer?
73s let me know how it worked out,
Rob ZS1AGX
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