Redifon NDB transmitter type G54 - UK Vintage Radio Repair and Restoration Discussion Forum

gm0ekm cecil · 31st Dec 2016, 6:08 pm

Quite a few years ago I was given a Redifon NDB transmitter type G54 which was being disposed of because the station had been upgraded. I didn't have any space to store it so I dismantled the transmitter and kept all the useful parts, valves, variable capacitors, inductors etc.etc. Many years later when I started using my 33' fibre glass vertical aerial (which was surplus from the same aerodrome) I built a modified L match coupling unit from the bits & peices from the ex ndb tx and installed it at the base of the aerial enabling me to transmit on 40 & 20m without any adjustment to the atu. Later on I added a inductor to the system with a manual switching to go on 160 & 80m. One evening 2 years ago I made contact on 80m. with 2 Japanese amateur radio stations, one gave me a 5/9 signal report and the other one a 5/7 I was running 400 watts from my vintage transceiver, I was pleasantly surprised to say the least. The original aerial coupling unit which formed part of the G54 now comes in very useful in my radio room for "dx'ing" aeronautical non directional beacons.
Enclosed is my home brew coupling unit.

GW3OQK Andrew · 31st Dec 2016, 6:38 pm

Cecil and everybody, I am preparing the humble pie for tonight's dinner. Well done on your atu. I see a picture of the of the 1948 G54 here http://www.aviationancestry.co.uk/?a...advertId=30593 but nothing better found. I suppose the transmitter fed coax and there was another tuner at the base of the remote NDB aerial.

I worked for Redifon in the 1970s but the G54 was before my time. Redifon made a solid state transmitter BK125 but by hearsay it could never beat the G54 for reliability or the ease of repair. Anyone abroad could change 807s but transistors were a different matter.

73, Andrew

31st Dec 2016, 6:08 pm	#1
gm0ekm cecil Tetrode Join Date: Jan 2008 Location: Shetland, UK. Posts: 79	Redifon NDB transmitter type G54 Quite a few years ago I was given a Redifon NDB transmitter type G54 which was being disposed of because the station had been upgraded. I didn't have any space to store it so I dismantled the transmitter and kept all the useful parts, valves, variable capacitors, inductors etc.etc. Many years later when I started using my 33' fibre glass vertical aerial (which was surplus from the same aerodrome) I built a modified L match coupling unit from the bits & peices from the ex ndb tx and installed it at the base of the aerial enabling me to transmit on 40 & 20m without any adjustment to the atu. Later on I added a inductor to the system with a manual switching to go on 160 & 80m. One evening 2 years ago I made contact on 80m. with 2 Japanese amateur radio stations, one gave me a 5/9 signal report and the other one a 5/7 I was running 400 watts from my vintage transceiver, I was pleasantly surprised to say the least. The original aerial coupling unit which formed part of the G54 now comes in very useful in my radio room for "dx'ing" aeronautical non directional beacons. Enclosed is my home brew coupling unit. Attached Thumbnails

31st Dec 2016, 6:38 pm	#2
GW3OQK Andrew Pentode Join Date: Apr 2011 Location: Swansea, Wales, UK. Posts: 144	Re: Transmitter ID Cecil and everybody, I am preparing the humble pie for tonight's dinner. Well done on your atu. I see a picture of the of the 1948 G54 here http://www.aviationancestry.co.uk/?a...advertId=30593 but nothing better found. I suppose the transmitter fed coax and there was another tuner at the base of the remote NDB aerial. I worked for Redifon in the 1970s but the G54 was before my time. Redifon made a solid state transmitter BK125 but by hearsay it could never beat the G54 for reliability or the ease of repair. Anyone abroad could change 807s but transistors were a different matter. 73, Andrew