"PDRUNEN" wrote in message
...
Hi Group,

Got a 706 which has a 500 or 600 ohm mic input impedance. I have a D104
which
best I can tell has a high output impedance.

If I use a 60Hz step down transformer, say, 120V in gives 10v out, the
turn
ratio is 120/10 or 12:1. Given that I attach the mic output to the
primary and
the rig on the secondary, this should step down the impedance by a factor
of
12^2 or 144 so that a D104 with 50K on the output is now seen as about 400
ohm.

Here are a few questions,

1: Will a 60Hz transformer work well keeping the base sound and pass upto
3KHz?

2: Is the calculation of the impedance correct?

3: Would the audio as seen on the secondary be reduced by a factor of 12
such
that the audio would be weak?

4: Other?

Tnx de KJ4UO

Paul -

Here are additional links on Astatic D104 restorations and "how to's" for
using with modern & Icom radios
... TIME FOR READING and PRINTING ...

W8CWE has a web page -- just what you are asking about (Google.com is great)
http://www.qsl.net/w8cwe/d104/d104.html

This is a D104 index you should "bookmark" in your browser
http://www.qsl.net/wa2mzf/d104.html

Doug DeMaw, W1FB (sk) FET circuit for D104 - CQ February 1994
(mentioned in web pages below)
http://www.qsl.net/wa2mzf/d1045.jpg

http://members.cox.net/n4jk/d104.htm

http://www.n9vv.com/K8LKC/k8lkc-d104.html

D104 and Icom equipment
http://www.qsl.net/wa2mzf/d104icom.jpg

IF you are looking for an 8 conductor coiled cord .. BUX COMM has a great
bargain 8FTCURLY at $ 1.99 !!!!
Would look nice on the D104
http://www.packetradio.com/xsinventory.htm

W9GB