For a band decoder, I like the Unified Microsystems device: http://www.unifiedmicro.com/decoder.html
To use this device, you would put +12 VDC on all the relay coils, and the decoder would ground the appropriate relay to pull it in. I would use cat 6 cable for the run out to the relays, with ground/signal on each twisted pair. Dave Hachadorian, K6LL Yuma, AZ -----Original Message----- From: Dennis Ashworth Sent: Sunday, February 25, 2018 2:50 PM To: elecraft@mailman.qth.net Subject: [Elecraft] Advice needed: Remote Station Enhancement I’ve been remoting my K3, KPA500, KAT500 station via the RemoteRig boxes and K3/0 mini for two years with solid results. Later this year, I want to make several enhancements, including the replacement of the KPA500 and KAT500 with a KPA1500. The amp/tuner should be a fairly straightforward hardware replacement, but it does necessitate a few station changes which I’m not certain how to implement. Let me explain and hopefully the masses have ideas/approaches for consideration. 1. I feed a HyTower vertical (optimized for 40M & 80M) on all bands. Where the driving impedance is close to 50 ohms on 40M & 80 (my bands of interest) there has been no attempt to match the HyTower on other bands. With the KAT500, matching was not a problem and I reduced mismatch losses on the feed line by using hardline from the in-shack tuner to the antenna. When I switch to the KPA1500, operation on the unmatched bands might prove problematic. To address this, I plan to provide switchable matching networks to transform the HyTower drive impedance on each band to something the KPA1500 can match. I can design the required impedance transformation networks, but not sure how to automatically select the various (relay based) impedance networks required for each band. Clearly, I need to grab band data from the K3, but what’s the best hardware to use for this task? BTW, I want to power the KPA1500 ON with the K3, which requires a Y-cable modification, or perhaps one of the N6TV boxes? 2. I want to interface a K9AY RX antenna 4 position switch to some sort of UI that I can access remotely. I can design an electrical interface to the K9AY switch, but controlling and monitoring remotely is the issue. Ideas? 3. I have a Windows computer available at each end of the radio circuit. The only other hardware is a SignalLink used for digital mods. 4. Configuring the station for future antenna enhancements (e.g. SteppIR if we live long enough to see sunspots return!) are great if they come without significant reliability impacts. Any ideas how to accomplish the required switching/monitoring? Thanks Dennis, K7FL Currently in Panama City, Florida Station in Battle Ground, WA Sent from my iPad ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k6ll.d...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
