Re: [Elecraft] k2 audio power
My Sony MDR 7506's have a DC resistance of 72 ohms per side. Since the phones are in parallel, the rig will see about 36 ohms. I am not sure how that relates to impedance but it seems in the ballpark. Heating and reactance would increase it some but I don't know by how much. They are comfortable and very sensitive. I bought them because of good reviews on eham. 73 - Rick - K7MW Sony MDR-7506 and MDR-V6 -- these are standard, large, closed headphones with nice soft cushions, work for for long operating sessions. These sell in the $100 range. Sony, being Sony, doesn't put impedance and sensitivity specs on the data sheets that I have, but I suspect they are in the same range as the ER4S's. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
[Elecraft] k2 audio power
All, I am just returning from a mountaintop weekend running the June QSO party in a multi-op environment. The k2 I supplied for the 222 station worked great, but there were several complaints, and I will be attempting to fix these before it's next excursion into this environment. The main complaint from all operators was audio power. There are 2 stations in the truck, and it is noisy with all of the amplifier fans and other local qrm. The volume knob on the k2 was never set below 3/4 to full for the entire weekend. When we used a second op for logging and Y'ed the headphones it was definitely at full throttle. I will at least add an external audio amp, but an internal mod would be good because I think it would be usefull even at home. There were other complaints too, but minor in nature. Manual PTT for cw being one of the other problems. With all of the external sequencing required for transverters and preamps and power amps, it would really be nice if the k2 would switch to tx when I pounce on the footswitch in cw. Other than that we pulled out the weak ones! Also, the agc off function was used well to make a couple of meteor contacts on 222. Lots of nice pings overnight. Ed wa3drc ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
Re: [Elecraft] k2 audio power
Ed: I used two K2's at W3CCX over the weekend. I found one of them to be usable under the multimulti conditions. That was not mine, but one built by John Sortor, KB3XG. He had mounted an auxiliary audio amplifier in the lid and it made a world of difference. We did over a million points for the first time in Packrats history. I will be adding external amplifiers to the ones I will be using for FD (2 transmitter, K2 QRP with AB2KT, W2GD, N2NT, N2NC, W2RQ, and other FRC'ers that show up) because it is simply a requirement for this kind of noisy environment. Bob N4HY Ed and all, Audio - I do use an external audio amplifier with the K2. CW PTT input - I am in the final stages of testing a mod to provide PTT in CW mode. It involves removing RF Board R1 and R2 and inserting a logic AND at that point. The only inconvience (which is not likely to be resolved soon) is that the same PTT input input used for CW will not function on SSB without manually changing an added switch. The normal mic jack PTT still work as it does now, and SSB VOX is not changed. If you would like to experiment with me, send me a note and I will scan the sheet with the schematic and instructions and send it to you. It will find its way to my website in due time. 73, Don W3FPR Life is what happens when you are making other plans - Original Message - I will at least add an external audio amp, but an internal mod would be good because I think it would be usefull even at home. There were other complaints too, but minor in nature. Manual PTT for cw being one of the other problems. With all of the external sequencing required for transverters and preamps and power amps, it would really be nice if the k2 would switch to tx when I pounce on the footswitch in cw. Other than that we pulled out the weak ones! Also, the agc off function was used well to make a couple of meteor contacts on 222. Lots of nice pings overnight. Ed wa3drc ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
