On 2015-06-16 1:29 AM, Jim Brown wrote:
FWIW, I have no use for the dedicated ham interface boxes no matter whose name is on them -- the wiring interface for the ones I've seen are an invitation to RFI and hum/buzz problems, and most have Pin One Problems. A very good USB sound card can be bought for $70 (see the ASUS U5 Zonar), You can build a WinKey for about $75, or the Yankee Clipper SO2R box for about twice that cost. A serial to serial cable is two connectors and some CAT5. Serial to USB adapters are inexpensive.
That's all well and good for someone with your experience and retired with time on his hands. However, when one counts the cost of all the individual *kit* pieces - $300 to $400 - add USB to serial converters (even though inexpensive they add up), a proper FSK interface like the K0SM or K8UT devices, includes the time to build/integrate everything, and then troubleshoot the interactions, the cost of dedicated ham interface boxes is very reasonable for a single box, plug and play solution. The pin 1 problems go back to the transceiver - there isn't a single amateur transceiver (that I know of) that properly bonds *all* signal returns to the chassis. Most of them don't even have a metal chassis any more and many of those that do use non-conductive enamel or power coating that prevents proper bonding in the first place. Everything is mounted on circuit boards with several inches of traces before the return signal actually reaches the chassis (if it ever does). Once the transceiver builds in a pin 1 problem, there is very little that an interface - yours included - can do to solve the issue. One can only use balanced connections, twisted pair cables, isolation transformers and bonding to minimize the problems. Add the tremendous lack of understanding about common mode RF (RF on the outside of the feedline) and complete ignorance issues of high current returns (TX current returning to a common power supply via accessories) and it's a wonder that most amateur stations don't have wore problems than they do. 73, ... Joe, W4TV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
