UK radio aids after WW2
Thread Starter
UK radio aids after WW2
This German/Swiss website has been expanded to include many UK airport charts, including approach and area charts.
interesting site 
Edit: A lot of the approach plates are labelled 'US DoD' so maybe it's from the flight bag of an American pilot.
Last edited by chevvron; 24th Oct 2022 at 09:19.
I looked up a couple of airfields that I know (Leconfield and Greenham Common) and I noticed that the ATC frequencies are in the 140-160 MHz range, above the current airband frequencies, which stop at 136.975 MHz.
Does anyone know the reason why these frequencies are no longer used? I couldn't find anything on the web.
Does anyone know the reason why these frequencies are no longer used? I couldn't find anything on the web.
I looked up a couple of airfields that I know (Leconfield and Greenham Common) and I noticed that the ATC frequencies are in the 140-160 MHz range, above the current airband frequencies, which stop at 136.975 MHz.
Does anyone know the reason why these frequencies are no longer used? I couldn't find anything on the web.
Does anyone know the reason why these frequencies are no longer used? I couldn't find anything on the web.
There were one or two 'standard NATO' frequencies outside the normal VHF airband; one was 142.29, another was 142.02 and another 136.8 which is now in the VHF airband.and unusually, 103.68 and 107.28.
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Other odd VHF frequencies from that era were:
116.46 RAF Uxbridge FIS?
117.9 NATO Tower Common
141.48 Fleet Air Arm common
142.29 was the RAF common approach frequency.
I once read a technical explanation of why these strange frequencies were used. I believe it was because they were obtained by modifying existing HF radios to VHF.
116.46 RAF Uxbridge FIS?
117.9 NATO Tower Common
141.48 Fleet Air Arm common
142.29 was the RAF common approach frequency.
I once read a technical explanation of why these strange frequencies were used. I believe it was because they were obtained by modifying existing HF radios to VHF.
The channel spacing in that era was 90 kHz (or 90kc/s in the terminology of the day), which I suggest accounts for the strange numbers. Sometime later (1960s?) the aviation standard changed to 50 kHz, then later 25 kHz, and currently (since the late 90s) 8.33 kHz, all in the interest of getting more channels into the available spectrum.
Other odd VHF frequencies from that era were:
116.46 RAF Uxbridge FIS?
117.9 NATO Tower Common
141.48 Fleet Air Arm common
142.29 was the RAF common approach frequency.
I once read a technical explanation of why these strange frequencies were used. I believe it was because they were obtained by modifying existing HF radios to VHF.
116.46 RAF Uxbridge FIS?
117.9 NATO Tower Common
141.48 Fleet Air Arm common
142.29 was the RAF common approach frequency.
I once read a technical explanation of why these strange frequencies were used. I believe it was because they were obtained by modifying existing HF radios to VHF.
VHF airband frequencies are currently 108 to 138 mHz AM with FM broadcasts 88 to 108.
Thread Starter
The channel spacing in that era was 90 kHz (or 90kc/s in the terminology of the day), which I suggest accounts for the strange numbers. Sometime later (1960s?) the aviation standard changed to 50 kHz, then later 25 kHz, and currently (since the late 90s) 8.33 kHz, all in the interest of getting more channels into the available spectrum.
It may also have something to do with the fact that a lot of (military) aircraft radios used crystals for their radios - none of that dialing up any frequency like you do today. I have a vague memory of having to specify the (12?) frequencies I wanted for a landaway in a Chipmunk, hence the NATO common frequencies made transits and approaches a lot easier. Even in the 70's our ILS's frequencies were still crystal controlled, so if you diverted it was not uncommon to find you couldn't use the ILS when you wanted it the most!
Thread Starter
It may also have something to do with the fact that a lot of (military) aircraft radios used crystals for their radios - none of that dialing up any frequency like you do today. I have a vague memory of having to specify the (12?) frequencies I wanted for a landaway in a Chipmunk, hence the NATO common frequencies made transits and approaches a lot easier. Even in the 70's our ILS's frequencies were still crystal controlled, so if you diverted it was not uncommon to find you couldn't use the ILS when you wanted it the most!
I don't own this space under my name. I should have leased it while I still could
135.95 IIRC was Bomber Common 2
115. 56 was Flying Training Common
There were 3 VHF Boxes. The RAF had two, one was high channels and the other low channels. The 3rd box fitted between the high and low and was fitted to RN aircraft AFAIK
On rangers the AEO would work out a crystal plan and swap out VHF boxes when in a new operating area. The STR 18 HF was also crystal controlled and sometimes would be recrystalised in flight.
115. 56 was Flying Training Common
There were 3 VHF Boxes. The RAF had two, one was high channels and the other low channels. The 3rd box fitted between the high and low and was fitted to RN aircraft AFAIK
On rangers the AEO would work out a crystal plan and swap out VHF boxes when in a new operating area. The STR 18 HF was also crystal controlled and sometimes would be recrystalised in flight.
From what I said a few years ago about 1950's frequencies:
Those 1950's pre UHF VHF frequencies brought back memories as to others implanted in my memory cells so long ago
e.g.
R.A.F. Common: 117.9 MHz
Fighter Command Common: 107.28 MHz
Transport Command Common: 135.9 MHz
Fighter Command Metropolitan Sector: 112.86 MHz, 135.18 and 153.9 MHz
...and ISTR that Bomber Command Common was around 101.xx MHz now the haunt of Classic FM.
e.g.
R.A.F. Common: 117.9 MHz
Fighter Command Common: 107.28 MHz
Transport Command Common: 135.9 MHz
Fighter Command Metropolitan Sector: 112.86 MHz, 135.18 and 153.9 MHz
...and ISTR that Bomber Command Common was around 101.xx MHz now the haunt of Classic FM.
