Fixing low SSB drive (updated)

Anders SM5NNO has drawn attention to a published fix for low levels of drive on SSB with BITx transceivers from Mr K P S Kang  (VU2KR / VU2OWF) on this blog.   While the mic gain fix relates to the BITx40, it translates readily to the uBITx.


An update

André PA3EIV confirms that the above fix (by Mr. K P S Kang VU2KR works 🙂

He changed the value of R65 to 4K7 and the value of R63 to 10 Ohm using 1206 surface mount components (desoldered from scrap prints).

He now has, on normal voice volume, 10 watt’s out on 20m.  RV1 is turned counter clockwise for about 75%.   André uses a Baofeng microphone.


An RF based AGC design from K P S Kang

K P S Kang VU2KR / VU2OWF has an item on his blog showing an RF AGC for BITx designs.  The AGC is apparently very effective at calming those 9+20dB signals that on the uBITx will damage your hearing!

The design is for the BITx40, but can be readily adapted for the uBITx – probably not at the antenna (because it is best to avoid diodes at the front end of the uBITx), but at the 45MHz IF stage.  Are there any takers to adapt this design for the uBITx?