[Premium-Rx] FW: Changes to extend the bottom response of the TR-7

[Carcia, Frank A. HS]

Hi All,
Enclosed the changes to improve TR7 audio from my friend Rob Schenck, K2CU

> Subject:	Changes to extend the bottom response of the TR-7
> 
> HI Frank,
> 
> Here are the components and their new values. They all have an impact,
> some more than others.  The only part that is at all tricky is the 1000 uF
> that replaces the 250 uF output coupling cap from the LM 380.  You need
> compact size part for it. I have some if you need one or more.  I will be
> doing some more work to make the top end drop off more quickly than it
> does presently.  I am also going to come up with a compact daughter board
> to add an autodyne detector for AM. I have found that you need to side
> tune the radio to optimize the use of the 4 KHz AM filter. When you do so,
> you end up with one sideband plus the carrier, as in A3H, and the extra
> distortion from the simple diode detector.  It may be possible to use the
> existing 1496 by using electronic switching to replace the BFO with the IF
> signal and self detect that way. A3H is best detected with either a true
> squaring circuit, or a synchronous detector. Well, anyway, here is the
> list:
> 
> Changes to extend TR-7 audio output response down to 35 Hz. top end stays
> at 2.6 KHz.
> All capacitors located on IF/detector/audio output board.
> 
> 
> C1159       1000uF
> C1153       100uF
> C1155       100uF
> C1152       0.1 uF
> C1150       0.47uF
> C1146       10uF
> C1170       10uF
> 
> 
> 
> ras
>