Larry My thinking was that worldwide folks are throwing away IBM Clones, which had a 20/40 pin floppy cable from the getgo. It provides the cables, and also mating connectors, required to use pins 1-6 with some spare pwr and ground.
OTOH. (Wally are you taking notes? Comments?) If we take Wally's design and put the 1-6 Mosfets on a simple "poor man's expansion board" and make it an optional connection we have the simple : 1. Foot switch and isolated amplifier switcher on a small screw in circuit board almost capable of being packaged in a backshell. Top or bottom mounted dual in line .025 post connector. And for those who wish: 2 add another six Opto Isolated switches for other amps etc on a ribbon connector and an external board. I think a 10 pin connector would do in that case. Instead of 20 or 40. Eric2 Still in suggestion mode. -----Original Message----- From: Larry Loen [mailto:[EMAIL PROTECTED] Sent: Tuesday, November 22, 2005 11:17 AM To: ecellison Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Subject: Re: [Flexradio] RFC - Poor Man's Universal Controller Board ecellison wrote: >Larry > >My thinking is that potentially everyone would like to have an inexpensive >ptt and amp interface which protects the radio. Some may like to play with >the other pins so a much lighter header could be provided to make the other >open collector pins available with a light readily available cable for >breadboarding a custom relay board with up to 6 relays, directly supported >in code. We don't want much feature creep in this one, just a compact screw >on unit. > >Again just an opinion. > >Eric2 > > > > OK, so which cable should it be -- floppy or IDE? And, should it be on the top? Neither of these questions represent feature creep (not as far as I can tell), just enough to get the design out the door and usable. But, I would hope the "other side" of the MOSFETs could take 12v or even perhaps 24v at ??? amps (presumably, not much amps). To me, half the point would be easy interfacing to the "analog world" out there, whatever it is. Common voltages are 5, 12, and 24, near as I can tell. Certainly, in my Harris Amp, I might eventually have to contend with switching all three of these, depending on how much of it I eventually decide to automate. Right now, my external antenna switch relay is running off 12v, because I didn't run out to digikey, but took what was available at Radio Shack to "just get going." That might be replaced, though, but I hate to remove working gear, however nominal the effort involved is. I'm not trying to make demands half so much as making a request to explain what the heck I will have and whether I need an added stage of buffering/amplification or not. For instance, if the system is limited to 5v, I'd need to put in a secondary circuit to move some of this stuff up from 5v to 12 or 24v perhaps. On the other hand, if this is mostly about grounding small amounts of control current (as I suspect it would be or could be) then maybe voltages aren't as big a deal. But, it would be good to know. Remember, at least one person involved in this transaction is not Mr. Electrical Engineer. As long as I can straightforwardly hook up my amp and, if I want to, also switch in a receive only beverage antenna perhaps (not my current need, but others have asked about this), we'd have a sufficiently robust design for a lot of folks to proceed to buy this thing. I know I want it regardless, but it would be nice, without dealing with feature creep, to make sure we've either got these bases covered plus explaining what supplemental circuitry these common applications are going to need. The optical isolation feature really appeals to me, however. I would much rather burn out this card than the SDR, obviously. Larry WO0Z
