Interesting, especially the decode number. Have you an opinion on the iMic?
73, Mike NF4L On 3/8/2012 8:59 PM, Jim Brown wrote: > in the last few days I've been evaluating a couple of low cost audio to > USB interfaces for use primarily with digital modes -- RTTY, PSK, JT65, > FSK441. My primary objective is to improve decode performance at low > signal levels. I studied the catalogs and chose two low cost units that > looked like they would do the job and would not have RF problems. > > Here's a link to a little Numark adapter that I bought for $33. t's as > cute and easy as it looks. Power from the computer, a couple of RCA to > 1/8-in cables for gozinata and gozouta. > > http://www.bhphotovideo.com/c/product/639303-REG/Numark_STEREO|IO_Stereo_iO_USB.html > > > The other one I bought is this Tascam unit. A bit larger, more > mechanically robust, mostly metal enclosure, more flexible with respect > to levels. The 1/4-in jacks for guitar and mic have more gain, so will > work with lower signal levels. $70 > > http://www.bhphotovideo.com/c/product/648495-REG/Tascam_US_100_US_100_USB_2_0_Computer.html > > > To evaluate them I hooked them to different Thinkpads running JT65-HF > and fed both of them from the line of a K3, then compared their decode > performance, and also compared them with the Thinkpads' internal sound > card. The two new adapters performed equally well, and often produced > almost twice as many decodes on a given pass as the the internal cards. > Next I transmitted through them and looked at their spectrum on a P3 > hooked up to a second K3. Distortion products look minimal on both units. > > I also pulled them apart and studied their construction. Both use > proper construction that avoids the Pin One Problems that cause RFI > issues. Now that I'm sure that they work well, I'm rewiring my station > to use them in place of the sound cards built into my Thinkpads for SO2R > contesting and everyday digital operation on both HF and VHF. > > Both of these units are a real bargain from well known audio vendors. > Their interface to the K3 (and other rigs) is really simple. They don't > do any control functions, so you still need a serial or USB to serial > for that. I use VOX to key the K3. > > Both are available from other vendors, but B&H had the best prices I > found, and shipping by UPS Ground was free. > > 73, Jim K9YC > ______________________________________________________________ > 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 > ______________________________________________________________ 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
