There were two versions of the CTCSS board and both used the same decoder chip...I version was a single tone with dip switches like the one he has...(but his was made by someone else) and the other one had a prom with a pig tail to the BCD switch to change the PL with channels. In his case he doesn't need the Prom as his is dip switch settable.
Gregg R. Lengling, W9DHI, Retired Administrator http://www.milwaukeehdtv.org K2/100 S#3075 KX1 S# 57 Politics is the art of appearing candid and completely open, while concealing as much as possible. -States: The Bene Gesserit View -----Original Message----- From: Ray Brown [mailto:[EMAIL PROTECTED] Sent: Saturday, November 22, 2003 1:57 PM To: [email protected] Cc: [EMAIL PROTECTED] Subject: Re: [Repeater-Builder] What is this board? ----- Original Message ----- From: "Adi Linden" <[EMAIL PROTECTED]> > > It is CTCSS encode/decode...didn't you see my other post....that's what > > the MN6520 chip is! > > Great! Thank you. Sorry, I didn't read your post until after I replied. > Any idea where I can find information on this chip? I've goggled for this > extensively before posting the question here. No useful results searching > the web. If it is the same chip used in the Kenwood 601/701/801 radios, it is a PROM chip that has a built-in decoding system, used with a programmer, to burn the PROM with info. A drop-in replacement for the chip is a 74ls188 PROM. Simply drop yours into a programmer, read it, analyze what you need to tweak, then burn it into a 188 PROM chip. I had a 601, a ham Elmer and I decoded what was on the chip, what it did, and decided that a PROM would be much easier to handle than getting the Kenwood programming tool. (In the 601, two chips controlled the xmit and rec frequencies, and a 3rd on a separate board did the CTCSS.) I thought I still had the old PROMs here, but I still have the first test-set of where these hard-wired pins will put a -601 on F1 at 52.525. Probably won't help you out, but it's in the right direction. :-) _Ray_ KB�STN Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
