Redifon GK203N - UK Vintage Radio Repair and Restoration Discussion Forum

radiozero · 27th Mar 2018, 5:44 pm

Hi. I've just acquired a Redifon GK203N. Firstly, I'm seeking a service manual for it. Anyone got one? Thanks. Rich

P.S. Any future posts will be how it works, correcting faults, etc.

G6Tanuki · 27th Mar 2018, 6:10 pm

Manual's on Elektrotanya.

They only give a very low power output - it's an "exciter": you'll be needing a decent linear amp if you want to work anyone with it!

Radio Wrangler · 27th Mar 2018, 6:54 pm

I used to have one. it was sold at the g-qrp doo back when it was held in George's church hall, along with its manual.

Output is about 200mW, so I built one of the Chris Honey 10W PAs for it and a bank of lowpass filters.

David

radiozero · 27th Mar 2018, 10:52 pm

OK, I got the manual. Thanks.

radiozero · 28th Mar 2018, 9:57 am

The Chris Honey PA is here, but only one page. I've pointed this out to the webmaster:-

http://myweb.tiscali.co.uk/m0khz/CIRKIT_PA_Page_1.PDF

Terry_VK5TM · 28th Mar 2018, 11:17 am

All pages here:

http://myweb.tiscali.co.uk/m0khz/html/20w_pa.html

G8BBZ · 28th Mar 2018, 11:32 am

Hi Rich,
GK203 nominal output is 100mW.
A weak point on these is the frequency standard - the gold coloured box at the rear right of the chassis. These fail but the buffer amp can then go into oscillation, producing a signal which the synthesizers will then try to lock to - usually with limited success.
Apart rom that i have found this equipment to be generally reliable, though the synthesizer may need alignment depending on how the unit has been handled and stored.
Good Luck
Peter G8BBZ

radiozero · 29th Mar 2018, 10:10 am

This might cause some to exlaim "Ouch" but I'm likely to completely dismantle this set and rebuild it in a different cabinet altogther and make mods.

I'll post pictures I think and ask for assistance.

G8BBZ · 2nd Apr 2018, 11:57 am

Hi Rich,
If you do go down the road of re-packaging the GK203 electronics I would be interested to take the front panel off your hands in the event it is not used in the re-build.
I have plans of my own to incorporate a receive chain into a GK203 to form a transceiver.
cheers
Peter G8BBZ

radiozero · 5th Apr 2018, 11:03 pm

Hi. Yes that would be fine. I've got the front panel off already. If you can PM me and give me address details I can figure out postage and that's all it will cost you. Rich

27th Mar 2018, 5:44 pm	#1
radiozero Hexode Join Date: Mar 2008 Location: Wakefield, West Yorkshire, UK. Posts: 444	Redifon GK203N Hi. I've just acquired a Redifon GK203N. Firstly, I'm seeking a service manual for it. Anyone got one? Thanks. Rich P.S. Any future posts will be how it works, correcting faults, etc. Last edited by radiozero; 27th Mar 2018 at 5:50 pm.

27th Mar 2018, 6:10 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,998	Re: Redifon GK203N Manual's on Elektrotanya. They only give a very low power output - it's an "exciter": you'll be needing a decent linear amp if you want to work anyone with it!

27th Mar 2018, 6:54 pm	#3
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,876	Re: Redifon GK203N I used to have one. it was sold at the g-qrp doo back when it was held in George's church hall, along with its manual. Output is about 200mW, so I built one of the Chris Honey 10W PAs for it and a bank of lowpass filters. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

27th Mar 2018, 10:52 pm	#4
radiozero Hexode Join Date: Mar 2008 Location: Wakefield, West Yorkshire, UK. Posts: 444	Re: Redifon GK203N OK, I got the manual. Thanks.

28th Mar 2018, 9:57 am	#5
radiozero Hexode Join Date: Mar 2008 Location: Wakefield, West Yorkshire, UK. Posts: 444	Re: Redifon GK203N The Chris Honey PA is here, but only one page. I've pointed this out to the webmaster:- http://myweb.tiscali.co.uk/m0khz/CIRKIT_PA_Page_1.PDF

28th Mar 2018, 11:17 am	#6
Terry_VK5TM Nonode Join Date: Oct 2010 Location: Tintinara, South Australia, Australia Posts: 2,339	Re: Redifon GK203N All pages here: http://myweb.tiscali.co.uk/m0khz/html/20w_pa.html __________________ Terry VK5TM https://www.vk5tm.com/

28th Mar 2018, 11:32 am	#7
G8BBZ Pentode Join Date: Oct 2005 Location: Hebden Bridge, West Yorkshire, UK. Posts: 200	Re: Redifon GK203N Hi Rich, GK203 nominal output is 100mW. A weak point on these is the frequency standard - the gold coloured box at the rear right of the chassis. These fail but the buffer amp can then go into oscillation, producing a signal which the synthesizers will then try to lock to - usually with limited success. Apart rom that i have found this equipment to be generally reliable, though the synthesizer may need alignment depending on how the unit has been handled and stored. Good Luck Peter G8BBZ __________________ Peter G8BBZ

29th Mar 2018, 10:10 am	#8
radiozero Hexode Join Date: Mar 2008 Location: Wakefield, West Yorkshire, UK. Posts: 444	Re: Redifon GK203N This might cause some to exlaim "Ouch" but I'm likely to completely dismantle this set and rebuild it in a different cabinet altogther and make mods. I'll post pictures I think and ask for assistance.

2nd Apr 2018, 11:57 am	#9
G8BBZ Pentode Join Date: Oct 2005 Location: Hebden Bridge, West Yorkshire, UK. Posts: 200	Re: Redifon GK203N Hi Rich, If you do go down the road of re-packaging the GK203 electronics I would be interested to take the front panel off your hands in the event it is not used in the re-build. I have plans of my own to incorporate a receive chain into a GK203 to form a transceiver. cheers Peter G8BBZ __________________ Peter G8BBZ

5th Apr 2018, 11:03 pm	#10
radiozero Hexode Join Date: Mar 2008 Location: Wakefield, West Yorkshire, UK. Posts: 444	Re: Redifon GK203N Hi. Yes that would be fine. I've got the front panel off already. If you can PM me and give me address details I can figure out postage and that's all it will cost you. Rich