+++++++++++++++++ From: "Nicholas Lokuciewski" To: elecraft at mailman.qth.net Date: Tue, 26 Mar 2002 22:49:03 Subject: [Elecraft] PSK31 interface? Dear All, Im looking to build a PSK31 interface to mount in the back of my K2. Other designs I have seen, require you to disconnect the microphone or use and external box/switch. I would like to make a more compact alternative. My main problem, is how to switch the audio that goes into the rig, from either the front panel mic connector or rear panel computer audio, without clicking or thumping. Any ideas? 73/72 M3LOK / 2E1LOK Nicholas K2 # 2448 +++++++++++++++++++ From: "Sverre Holm - LA3ZA" To: "'Nicholas Lokuciewski'" , Subject: RE: [Elecraft] PSK31 interface? Date: Wed, 27 Mar 2002 00:08:28 +0100 I have looked at this also, and listed the three different published alternatives that I have found on my K2 modifications page (http://www.qsl.net/la3za/K2/mod.html#PSK31). Basically, there seems to be three alternatives around: - Basic set up with cables to connect/disconnect and no mods inside the K2 (WA7SPY) - An external switchbox (W3FPR) with few mods to the K2 - An internal board that automatically switches over on the computer's PTT (EA3BLQ) The last solution is the most elegant one, but unfortunately it is not compatible with the KAF2. I have discussed this with Pauli, EA3BLQ. My idea for an internal board is one that could be put in the corner of the cover where the loudspeaker connector is now. Here one could put a 6 pin mini-DIN connector for the i/o. The board size can be like the KIO2 board (3.8 x 3.8 cm), and the mini-DIN and a new loudspeaker connector have to be mounted on the board. Most likely there will be no room for the mike configuration header, so that will have to be done by using different extension cables between the cable coming form the front-panel board and the plug on the PSK31 board. That would copy all the functions from the EA3BLQ baord in a smaller board that would fit even when the KAF2, the KAT2, the KIO2 and the battery options are fitted (Most likely it would not fit with the 100 W power option?) An idea from the W3FPR switchbox is to disable the audio compresison automatically in digital mode. His 2-transistor circuit or just a diode with plus to the KSB2 board and minus to the digital PTT line could do that. In addition the output to the computer should be after the KAF2 board, and this is simple by adding a connector to the KAF2 board. So far these are just some ideas. I would be very happy for some input from other K2 users and especially those that are familiar with PSK31 and other digital modes. 73, Sverre Sverre Holm, LA3ZA Asker, Norway --------------------------------- www.qsl.net/la3za +++++++++++++++++ From: "Nicholas Lokuciewski" To: la3za at qsl.net, elecraft at mailman.qth.net Subject: RE: [Elecraft] PSK31 interface? Date: Tue, 26 Mar 2002 23:36:40 Cheers Sverre! The 'K2 digital interface' from EA3BLQ was what I was looking for! Just want to know what the switching performance is like (noisy, clicky, etc...)? 73 Nicholas +++++++++++++++++ From: "Dan Barker" To: "Elecraft" Subject: FW: [Elecraft] PSK31 interface? Date: Tue, 26 Mar 2002 19:33:03 -0500 I use the front panel jack, but I don't use a mic. My cable has a fat spot with 1 transistor, one diode and one resistor = (for PTT) and the rig has AF Out to pin five of the mic jack. Certainly is minimal, but of course the computer end has three plugs = (DB9 and two stero plugs). But no box is needed, just some fat shrink-fit around the components. Dan / WG4S / K2 #2456. Photo upon request. Im looking to build a PSK31 interface to mount in the back of my K2.=20 ++++++++++++++++++