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ICOM IC-502

Posted: Sat Jul 19, 2014 11:14 am
by ZL1RQ
I have just come into possession of an old IC502 that operates on 52 Mhz.
Does anyone have info on how to mod for 50 Mhz.

Alan VK4WR

Re: ICOM IC502

Posted: Sat Jul 19, 2014 12:07 pm
by ZL3MH
Yes they came from Japan tuned from 50 to 51MHz. They were retuned in VK and ZL
to cover the 52 MHz band for 52.050. I did one some time ago back to 50 to 51MHz.
The VFO was easy, just retune the big can. The rest of the reciever was a bit harder
as the slugs braked very easy . All the best Murray ZL3MH

P/S still have the IC202s and the IC402

Re: ICOM IC502

Posted: Sat Jul 19, 2014 12:11 pm
by ZL3MH
The IC202s with a HB 80w amp on 2m and the 2m to 6m Transverter and 80w HB 6m amp

73 Murray ZL3MH

Re: ICOM IC502

Posted: Sat Jul 19, 2014 12:13 pm
by ZL3MH
Inside the 3 to 80w 6m amp

Murray ZL3MH

Re: ICOM IC502

Posted: Sat Jul 19, 2014 2:33 pm
by VK6SIX
These things have an IF around 13.9mhz. ?

Do not transmit on 14mhz band if the 502 is switched on.

They get very upset at any 14mhz rf straight into the IF !

I have emailed you some photos from the owners manual

All the info you need is in the owners manual in the adjustment section.

My first contact on 6 in about 1979 was with a ic502 barefoot from the mobile into a 1/4 wave mobile whip. After that i worked hundreds of jas from the mobile over about 2 years with 2.5 watts

Also do not reverse the DC polarity or you will not be happy!

vk6six/ro

e&oe

Re: ICOM IC-502

Posted: Sat Jul 19, 2014 9:49 pm
by VK4GHZ
It's always preferable if we reply via the same means: ie ON forum.
This can always help others down the track.
(The forum rates well with Google)
IC-502A.pdf
Icom IC-502A Manual
(5.67 MiB) Downloaded 400 times
IC-502 Schematic.pdf
Icom IC-502 Schematic
(398.31 KiB) Downloaded 278 times
I seem to remember a conversation today Alan, involving Tsingtao. :beer:

Re: ICOM IC-502

Posted: Sun Jul 20, 2014 12:46 pm
by VK3PY
For owners of IC202's and its brethren, this may be of interest:

http://www.qsl.net/k5bcq/Kits/Kits.html

It's a neat little frequency synthesiser based on the Si570 PLL chip. It features an LCD read-out with frequency resolution to 1Hz and memory channels, as well as the facility to program an IF offset so it displays the actual operating frequency. I built one for my IC-202 just for fun. I gutted the main board from my '202 and re-housed it, together with the PLL into a nice box, but the '202 series of rigs feature an external VFO input, so this PLL could be built into a small enclosure and simply plugged into the radio.

I frequently use my "IC-202D", as I have dubbed it, as a tuenable IF for my microwave transverters. It's a really neat, easy-to operate little radio.

Chas
VK3PY