Audio filters are a topic close to my heart for obvious reasons -I'm pretty deaf & need all the help I can get!
I just visited
http://newenglandqrp.org/store and I ordered a NEScaf switched capacitor audio filter kit plus the connector pack. For the first time in a long time they were in stock. I chose to pay by Paypal so the whole process was over in less than a minute. Total cost? $42 including post and packaging which translates to £26 or 31Euro at today's rate of exchange. The schematic and manual are available for download from the site. This is considered a classic cw filter which I didn't think to mention before because it has been out of stock for a while. Is it any good? Judge for yourself:
Disadvantages: build it & case it yourself. Post not like lightning.
Advantages? build it & case it yourself (bragging rights) & classic kit (bragging rights
) Small case possible so good for /P.
Vic /nipping aloft to winch the bilges....