[Heathkit] Audio filter on HR-10B

[Harry Vaught, KT4AE]

I have a couple of the Radio Shack DSP-40's.  One is on my SX-101A and 
the other on the SX-117.  They give a range of sharp cutoff bandwidths 
much more useful than those on the receivers.  They come in very handy 
in SSB and CW.  They're discontinued and I bought mine at clearance 
prices.  I see them all the time at hamfests.

They're called DSP's, but I don't know how much DSP'ing they do. 
They're not much for noise reduction, but are good audio filters.

Harry, KT4AE
Maryville, Tennessee