RAF Common 117.9
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RAF Common 117.9
I will kick this off for those that recognise the title.
Do you have numbers that are engraved in your memory? How many can remember the Common frequencies let alone remember the numbers?
When did the RAF first create common RAF and Command? It was when crystalised VHF R/T was the main radio system. There were 3 boxes, one was lower VHF and the third higher. The RN had the one in the middle. I can't remember the ranges but the lower frequency was near 112 MHz and the upper near 140 MHz.
The channels I remember were;
RAF Common 117.9
Flying Training Command Common 115.56
Bomber Common Two 135.95
When flying outside controlled airspace, which was pretty much most of the country, we would monitor at least one Common.
Does anyone remember the other Common freqs?
Do you have numbers that are engraved in your memory? How many can remember the Common frequencies let alone remember the numbers?
When did the RAF first create common RAF and Command? It was when crystalised VHF R/T was the main radio system. There were 3 boxes, one was lower VHF and the third higher. The RN had the one in the middle. I can't remember the ranges but the lower frequency was near 112 MHz and the upper near 140 MHz.
The channels I remember were;
RAF Common 117.9
Flying Training Command Common 115.56
Bomber Common Two 135.95
When flying outside controlled airspace, which was pretty much most of the country, we would monitor at least one Common.
Does anyone remember the other Common freqs?
362.3 is stuck in my memory. After the change to UHF sets, this was the only frequency we had in UBAS Chipmunks, that could be used to talk to other RAF towers during cross-country flights. I remember one air-trafficer, possibly at Syerston, who was surprised and disbelieving that we couldn't switch to Approach.
Does anyone remember the other Common freqs?
VHF was superseded by UHF in the early 60s; UHF first met by me at Leeming on the JP, 61-62, but back to VHF for the Vampire at Valley 62-63.
From elsewhere:
As late as 1973, our ULAS Chipmunks still had ancient 10-ch VHF sets, complete with utterly useless obsolete VHF frequencies. No doubt there was some aged Learning Command edict, which no-one had reviewed, stipulating that 'RAF Common' and 'NATO Common' frequencies were to be carried?
When the RAF woke up to extension of the aeronautical VHF band from 136 to 137 MHz, the only way this could be achieved on some of our VC10K V/UHF radios was by sawing off some internal mechanical part, to enable the VCO to go up that high. But this also had the effect of lowering the bottom available frequencies by 1 MHz...
, which would have caused interference to some navaids.
The only RAF aircraft I flew which had the full range VHF band (up to 150-ish MHz, I think) was the Hawk T1. Tootling back along a TACAN route from Scotland back to Chivenor once using UHF, I clicked through the VHF radio's channels to see what was there as the coverage included various 2m frequencies used by taxis and other mobile users - as I soon discovered!
At the end of WWII the military air VHF band was 100-156MHz. Transmit frequencies were derived from crystal oscillators working in the range of 5.560MHz to 8.665MHz which were electronically multiplied by 18 to give the transmitter output freq.
The oscillator crystals were manufactured at 5KHz spacing, which when multiplied by 18 gave an output channel spacing of 90KHz. Thus there were some 622 channels available from 100.08MHz to 155.97MHz at the end of WWII.
When civilian aviation started they were allocated 108-128MHz initially (100KHz channel spacing). 108-118MHz was allocated to navaids and 118-128MHz to R/T. The old RAF common freq of 117.9 was so widely used, that it must have been kept clear of navaid use until the RAF finally gave it up. Many civil aircraft also carried 117.9 (it was only a matter of plugging the appropriate crystal in).
The oscillator crystals were manufactured at 5KHz spacing, which when multiplied by 18 gave an output channel spacing of 90KHz. Thus there were some 622 channels available from 100.08MHz to 155.97MHz at the end of WWII.
When civilian aviation started they were allocated 108-128MHz initially (100KHz channel spacing). 108-118MHz was allocated to navaids and 118-128MHz to R/T. The old RAF common freq of 117.9 was so widely used, that it must have been kept clear of navaid use until the RAF finally gave it up. Many civil aircraft also carried 117.9 (it was only a matter of plugging the appropriate crystal in).
When the RAF woke up to extension of the aeronautical VHF band from 136 to 137 MHz, the only way this could be achieved on some of our VC10K V/UHF radios was by sawing off some internal mechanical part, to enable the VCO to go up that high. But this also had the effect of lowering the bottom available frequencies by 1 MHz...
, which would have caused interference to some navaids.The only RAF aircraft I flew which had the full range VHF band (up to 150-ish MHz, I think) was the Hawk T1. Tootling back along a TACAN route from Scotland back to Chivenor once using UHF, I clicked through the VHF radio's channels to see what was there as the coverage included various 2m frequencies used by taxis and other mobile users - as I soon discovered!
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BEagle's mention of 100 MHz reminds me about the RBS frequency used at EAR West Freugh. I think that was the frequency used by the Vulcan's practising pop up attacks..
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From memory - so therefore probably very wrong:
NATO common Approach: 362.3 122.1
NATO common Tower: 257.8 122.1
NATO common Director: 344.0 123.3
NATO common Talkdown: 285.4 123.3
NATO common Fixer: 317.7 ????
I also remember the 142.29 mentioned above on the very old 10 channel VHF ATC standby boxes; the only time I saw it slated for use was in conjunction with some post-apocalyptic Civil Defence/ROC exercise. Needless to say it didn't do what it said on the tin! I think 117.9 may have also been on those antideluvian VHF boxes too, labelled simply 'Common'.
NATO common Approach: 362.3 122.1
NATO common Tower: 257.8 122.1
NATO common Director: 344.0 123.3
NATO common Talkdown: 285.4 123.3
NATO common Fixer: 317.7 ????
I also remember the 142.29 mentioned above on the very old 10 channel VHF ATC standby boxes; the only time I saw it slated for use was in conjunction with some post-apocalyptic Civil Defence/ROC exercise. Needless to say it didn't do what it said on the tin! I think 117.9 may have also been on those antideluvian VHF boxes too, labelled simply 'Common'.
Last edited by Downwind.Maddl-Land; 27th Nov 2018 at 19:21. Reason: Pressed submit before completion
As late as 1973, our ULAS Chipmunks still had ancient 10-ch VHF sets, complete with utterly useless obsolete VHF frequencies.
Does anyone remember the other Common freqs?
- R.A.F. Common: 117.9 MHz
- Fighter Command Common: 107.28 MHz
- Transport Command Common: 135.9 MHz
- Bomber Command Common: 103.86 MHz
- Fighter Command Metropolitan Sector: 112.86 MHz, 135.18 and 153.9 MHz
Last edited by Warmtoast; 27th Nov 2018 at 21:04.
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Warmtoast, knew someone would know. Almost the complete set there and also the NATO.
If you flew out of area you needed a specially crystallised box for instance to fly from UK to NATO. I remember the AEO swapping boxes inflight as we flew from UK to Malta. Also swapping the crystals whilst airborne.
The Russians only had 4 channels in their fighters so the V-Force comma jamming just aimed to deny them their fighter common. A cunning plan but I think there was a flaw in it
If you flew out of area you needed a specially crystallised box for instance to fly from UK to NATO. I remember the AEO swapping boxes inflight as we flew from UK to Malta. Also swapping the crystals whilst airborne.
The Russians only had 4 channels in their fighters so the V-Force comma jamming just aimed to deny them their fighter common. A cunning plan but I think there was a flaw in it
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Warmtoast, those VHF/DF operators were a boon to baby navs. Wending our war up to Wooler on early radio position line exercises the pilot would call up MsG or Acklington for a QTE. After a pause to allow for the reply we might hear ABC12 this is Silloth, your bearing that time was nnn. Two for the price of one.
There was also a deal with the Scily Island Homer. They would bill the RAF for each bearing. Using them meant they got paid; if they got paid they stayed open
There was also a deal with the Scily Island Homer. They would bill the RAF for each bearing. Using them meant they got paid; if they got paid they stayed open
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Do y'all know those crystals were valued at £10.00 each?
As a Corporal at Dishforth c1959, at the start of each shift I had to sign for a whole cupboard full of hundreds of the damn things. This was the ARSF 'Crystal Bank!
Each pre-flight, we had a 'Crystal Fit' that was dependent on where the a/c, Hastings & Beverley's, were going to.
A nightmare it was checking all of the crystals in and out and trying to keep a record of which a/c they were all in, and which wireless mech had left one in his pocket.
As a Corporal at Dishforth c1959, at the start of each shift I had to sign for a whole cupboard full of hundreds of the damn things. This was the ARSF 'Crystal Bank!
Each pre-flight, we had a 'Crystal Fit' that was dependent on where the a/c, Hastings & Beverley's, were going to.
A nightmare it was checking all of the crystals in and out and trying to keep a record of which a/c they were all in, and which wireless mech had left one in his pocket.
I remember Oakington (Varsity) in 1970/71 doing the planning for an ‘airways trainer’, and having to look up the various crystals we would require, and to tell the flight line engineers which ones we wanted for the trip.
We got airborne and joined airways at (I think) BPK and started along the airway to CLN. After a few mins we were told to contact London on a frequency we didn’t have in the box.
There was a waving of instructor hands and an instruction to acknowledge the frequency change and then to keep quiet.
After about a min. the said instructor calls London, on the original frequency, and says that we had no answer on the new one just given.
The reply from London was a request to tell him the frequencies of the crystals we did carry! All a bit embarrassing.
We got airborne and joined airways at (I think) BPK and started along the airway to CLN. After a few mins we were told to contact London on a frequency we didn’t have in the box.
There was a waving of instructor hands and an instruction to acknowledge the frequency change and then to keep quiet.
After about a min. the said instructor calls London, on the original frequency, and says that we had no answer on the new one just given.
The reply from London was a request to tell him the frequencies of the crystals we did carry! All a bit embarrassing.
In the rear crate of our Canberras there were 8x 10 channel VHFs and these quite often needed "fit" changes according to instructions passed down from high.
Quite a job for our w/t engineers, fortunately, being radar, this job didn't apply to me but I can still remember helping by carrying a bag full of Xtals and passing the appropriate one when asked as my mate tuned them. Happy days.
Quite a job for our w/t engineers, fortunately, being radar, this job didn't apply to me but I can still remember helping by carrying a bag full of Xtals and passing the appropriate one when asked as my mate tuned them. Happy days.
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Pontius
Down Start Point way I requested a QTE from Culdrose, the pilot refused saying always use Scily Homer support them the R.A.F. have to pay 2/6d for each bearing. Even better was a running fix for 7/6d, the only trouble was it was a manual homer and often class 3!
Somewhere in the depth's of Pprune Military there is a thread on "The Dulcet tones of Silloth".
Down Start Point way I requested a QTE from Culdrose, the pilot refused saying always use Scily Homer support them the R.A.F. have to pay 2/6d for each bearing. Even better was a running fix for 7/6d, the only trouble was it was a manual homer and often class 3!
Somewhere in the depth's of Pprune Military there is a thread on "The Dulcet tones of Silloth".
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Yes, I remember 117.9. From an ATC point of view, I certainly remember the comely young ladies who had to monitor all the common frequencies from a compartment behind the approach room. As an 18 yr old newly minted Plt Off at Little Rissington (c 1961) they were a bit intimidating - eyeing you up and assessing you while doing their knitting or reading, earphones on their heads. Quite put me off learning about integrating high & low level QGHs.
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Pom Pax, TY, confirms my memory and agree on running fix. Our trips were assessed on 'activity point's and 'process points'. The more points accrued the less significant mathematical errors.
We soon learnt to 'discard ' one of the 3 bearings and construct a 2 position line MPP thus gaining both activity and extra process points
Might not have been best navigation but certainly best system.
We soon learnt to 'discard ' one of the 3 bearings and construct a 2 position line MPP thus gaining both activity and extra process points
Might not have been best navigation but certainly best system.
PN
I did a piece here on PPRuNe about my days as a VHF/DF Operator that includes a full listing of UK "VHF/DF Fixers" in the early 1950's. See here:
RAF Fighter Command VHF/DF Fixer Net Early 1950's
Warmtoast, those VHF/DF operators were a boon to baby navs. Wending our war up to Wooler on early radio position line exercises the pilot would call up MsG or Acklington for a QTE. After a pause to allow for the reply we might hear ABC12 this is Silloth, your bearing that time was nnn. Two for the price of one.
RAF Fighter Command VHF/DF Fixer Net Early 1950's
Ian 16th - Ah yes, the Crystal Bank! At Dishforth and Abingdon we used to collect a 'Route Pack' of Xtals for the VHFs and the STR18s dependent on which route we were on. Over the years I , somehow, 'collected' a personal stock of the most useful which lived in the Nav bag pencil box (still have the box!) When I eventually left Abingdon for Bangkok, I tried to hand in these 'extras'. NO way!! The chap in charge didn't want to know - the addition of some dozen or so xtals to his aready audited stock would create HUGE problems!! 
Also swapping the crystals whilst airborne.
I've always thought that simply pushing buttons to select a new frequency is for sissies.