I have four 4N29s in my stock. I'll send you one for free. I think the 4N29 will do the trick. The 4N29 will give 2500 Vdc isolation. They cost 20 cents.
Please confirm your address off list to my E-mail at [EMAIL PROTECTED] and I'll pop one in the mail for you. The transformer can be anything close as the impedance for your radio output is probably 8 ohms and the input to the computer is around 5K ohms. I do not use any transformers in my setup. http://www.w5bbr.com/soundbd.html has some alternative suggestions. The isolation transformer prevents ground loops. Try what you have from the junk boards. You can also wind a small transformer on a ferrite core. Check google for design parameters. If you have some ferite beads, you should place one on the input and output audio lines; that should help as well. I would recommend placing all your interface components in a shielded box. I mounted RCA jacks on the back of my interface box for the input and output interfaces and then used standard audio patch cords which can be purchased already made up. 73, Bernie ----- Original Message ----- From: Bob To: digitalradio@yahoogroups.com Sent: Monday, January 22, 2007 10:27 PM Subject: Re: [digitalradio] PSK and Yeasu ft-101 Hi Bernie, Thanks for the info Does the transformer have to be a 600 ohm, I have some junk boards here I may be able to scrounge a few from, but not sure of their value. And yes I could use one of them 4N35's I would gladly pay you for it. The schematic you refered me to was one I was looking at. The radio is very stable after about 45 min. I allready have the line in to the computer set up and using digipan. 73 Bob KC9GMN ----- Original Message ----- From: ve3fwf To: digitalradio@yahoogroups.com Sent: Monday, January 22, 2007 7:22 PM Subject: Re: [digitalradio] PSK and Yeasu ft-101 Have a look at http://www.geocities.com/n2uhc/interface.html This is the opto-isolated circuit I initially built for my HW-100 and it works just fine with the ICOM radios. The above circuit should work on your FT-101. The important thing is that the rig should not drift. While a jump of 50 Hz is OK on SSB, it will cause loss of signal on digital. You will be able to spot a drifting problem by watching the signals on the waterfall. I can send you a 4N35 if you can't source one locally; I'm fairly certain I have some spares. Radio Shack used to have 1:1 600 ohm transformers but I don't know if they still carry these anymore. Good luck and join the fun on digital. 73, Bernie ----- Original Message ----- From: Bob To: digitalradio@yahoogroups.com Sent: Monday, January 22, 2007 7:18 AM Subject: [digitalradio] PSK and Yeasu ft-101 Hi Gang! I am fairly new here to this group and have been reading some of the posts. I would like to know if anyone here is using a older rig like mine, a Yaesu FT-101 Z and running PSK31 mode, and what kind of interface they are using. I have seen several schematics for homemade interfaces and am unsure which would be the best to use, I have a 1.8 GHZ computer and a sound card in it. Thanks Bob KC9GMN ---------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.4/644 - Release Date: 1/22/2007 7:30 AM
