Yet another Mosquito wireless question

[Crimea River]

Hello all. Hopefully I haven't scared you all off with this subject as I know it's been brought up at BM before. Nonetheless, I'd really like to hear from this enlightened group as I have spent several hours trolling the net and related topics on this forum but remain mystified.

 

The question relates to the wireless equipment fit-out on Mosquito F.B. VI HR147 "Hairless Joe" of 418 Squadron RCAF. I'll be starting a build thread soon but, as always, I try to research my subject before laying significant amounts of glue to plastic. The kit I plan to use is Tamiya's 1/48 F.B. VI/N.F. II which provides the oft-seen T1154/R1155 equipment as the only option. However, based on what I've read in Air Publication 2019E I'm fairly certain that this aircraft would have been fitted with Gee, since it states that only a few Mosquitoes in the HJ series carried the T1154/R1155 equipment without Gee. What has me stumped is this paragraph in the A.P:

 

 

The Gee equipment, which effectively displaces the old T1154/R1153 setup from it's previous perch in the cockpit, is shown here:

 

 

What has me stumped is that the A.P states that the R1155 is retained (the T1154 being apparently eliminated) and that the unit is carried next to the Gee receiver on the rear deck like so:

 

 

So, here goes:

 

1) What would have been the purpose of carrying the R1155 without its attendant transmitter? I've read that the R1155 was sometimes combined with a D/F loop but my pea-brain would conclude this to be irrelevant with Gee. Note that this radio set-up also includes the T.R.1143. 

2) Was the aerial mast always associated with the R1155? Where would the lead wire go? I believe, maybe wrongly, that the T1154/R1153 antennas ran from the mast to the fin and port tailplane but, if that's true, I don't know which was which. So if the R1155 was retained along with the mast, do I keep an antenna wire?

3) Was this set-up "real" and was it eventually replaced with something else? I have seen the pic of a Gee set-up in a Mosquito which shows an empty rack adjacent to the Gee receiver. I ask this because of the documentation provided with @Terry @ Aviaeology 's excellent Aviaeology decals which states that the mast was present on this particular aircraft originally and then appears to have been removed later. None of the pics provided in the documentation show the mast and, for that matter, the Gee whip isn't visible either.

 

Thanks for reading this and I hopefully there will be some good info coming to fill the spaces below! Ultimately, I will want to make an educated decision on the equipment to be carried in the cockpit as well as the associated antennae. 

 

Andy

 

 

[dogsbody]

If I've re-read the information right, GEE worked by sending signals from two separate transmitters in England to the receiving aircraft. Maybe they only needed the R1155 to receive that signal.

 

 

Chris

[Peter Roberts]

Crikey - here was I thinking I'd just shove some non-descript black boxes in behind the pilots seat. Great questions, great post. Will follow this one with interest, and try to understand what is raised. Well, hope springs eternal - that last bit may be a bit premature

 

PR

[Grey Beema]

I'm building an NFXIII and asked about what goes on the back shelf etc as the radio fit was different for the XIII.

 

https://www.britmodeller.com/forums/index.php?/topic/235054852-another-mosquito-question/&tab=comments#comment-3339709

 

In the end I scratch built the back shelf equipment and a Gee unit however the Tamiya canopy is quite thick and the view into the cockpit is obscured.  Once your cockpit is built, it might be worth considering an after market canopy to get a good view into the cockpit.

 

 

 

Good luck with your build..

 

 

 

[Crimea River]

13 hours ago, dogsbody said:

If I've re-read the information right, GEE worked by sending signals from two separate transmitters in England to the receiving aircraft. Maybe they only needed the R1155 to receive that signal.

 

 

Chris

Hi Chris and thanks. Gee came with its own receiver that was independent of the R1155 as far as I know. See the A.R.I 5083 diagram above. The Gee receiver is the box on the deck behind the sloped indicator unit.

 

Peter, thanks for your interest and hopefully this goes somewhere!

 

Grey, thanks for your info and link. Hadn't come across that one in my journey but it still doesn't explain the apparent presence of the R1155 along with Gee. Your tip on the canopy is duly noted and I'll look at possibly getting a vac-formed one.

 

Andy

 

 

[tango98]

PM inbound Andy.

 

Dave

[Work In Progress]

My understanding, based on a pretty detailed and internally coherent wikipedia article, is that Gee did not depend on airborne transmission, unlike Gee-H. All Gee needed in the aeroplane was the receiver, and the oscilloscope for display.

https://en.wikipedia.org/wiki/Gee_(navigation)

[Crimea River]

Thanks WIP, interesting, though the FB VI manual does show the control unit mounted in the mid fuselage. There's also some evidence that the control unit may have been mounted on the wing shelf in the cockpit.

 

This discussion has taken on new life here: https://ww2aircraft.net/forum/threads/gb-43-1-48-mosquito-fb-vi-aces-aircraft-of-all-eras.51641/page-2 starting in post 27. More comments welcome.

 

Andy

[junglierating]

Hi ,I've only had a quick look but Gee is a radio nav aid used to establish position by basically comparing two slightly different HF radio signals which are received at slightly different times.

Whereas the radio set 1155? Is a two way HF radio.....infact Gee is also HF and a little of VHF ....gotta look into this a bit more. So they have different jobs ....radio and radio nav aid hence why both are fitted.

Like I said only a quick look but I dont think I'm far wrong ....sorry if I'm teaching u to suck eggs.

Not really modelling but nonetheless very interesting ....Radio fit on aircraft are so much more complicated in the different fits they have ...add green comms and it gets even more interesting🤪😁

[Crimea River]

Thanks for that. The distinction between Gee and the R1155 unit is not in question. My issue originated with the apparent deletion of the T1154 transmitter but retention of the R1155 receiver as well as Gee. It is really boiling down to what, in addition to the Gee indicator and receiver, should be included on the "shelf" of my FB VI model.

[junglierating]

Hello again ....I'm more confused as per the AP I can only assume that there must be a 1154 Tx somewhere else on the aircraft since they would have no long range comms or at least they could only listen using the 1155 Rx.

The 1143 is an TR but only with limited VHF freq.

The 5010 is IFF so unless GEE Mk2 also has a tx function I'm not sure how they would communicate back to UK.

Still need to research more ...I'll fit it in between what I'm doing on Merlin Comms equipment 

[Crimea River]

Thanks, My understanding is that the R1155 was eventually removed as well, evidence being the disappearance of the mast. I will be modeling my bird without the R1155 but would still love to know how the unit would have been used in the AP set-up without the T1154.

[junglierating]

Hmm makes no odds form modelling purposes but if that was the case the aircraft would only have  a relatively short range VHF radio for comms so that doesnt really make any sense....

[Crimea River]

...and so we have come full circle. The AP says that the R1155 was retained, fitted alongside Gee, and the T1154 deleted. That's why I asked the question.

[Jonny]

Folks,

 

Do, please, look at the material that Work in Progress provided (Post 7).

 

That material refers to R1355, not R1155.  I’m not sure what the physical difference between the 2 receivers was, but if the equipment numbers changed there must have been some, and probably significant ones, too.

 

Please be aware that the Wikipedia photos are of equipment displayed in a museum, not of anything actually installed in a Mosquito.  I rather think that the photos might be of radar equipment at the RAF Neatishead museum, in the UK.  When I've time I’ll look up the snaps I took at Neatishead some time ago.

 

Somewhere, in the dim & distant past, I seem to recall seeing a photo of a Mosquito cockpit with the GEE display unit installed immediately behind the pilot’s seat, angled so the Navogator could see and use it.  Behind that were the boxes associated with normal radio equipment.  God only knows where, or of what, the photo was of!  Sorry.

 

Hope this helps,

 

Jonny

 

 

Edited September 1, 2019 by Jonny
Correcting s typo

[Seahawk]

15 hours ago, Jonny said:

Somewhere, in the dim & distant past, I seem to recall seeing a photo of a Mosquito cockpit with the GEE display unit installed immediately behind the pilot’s seat, angled so the Navogator could see and use it.  Behind that we’re the boxes associated with normal radio equipment.  God only knows where, or of what, the photo was of!  

Rings a bell with me as well.  Were I at home with my references, my first port of call would be one of Martin Streetly's books on 100 Group, probably the modelling-focussed "The Aircraft of 100 Group".  Lots of shots like that, not always with a terribly direct 100 Group connection.

[Pete M.]

And just to confuse this question further, below is a sketch I have in my Mosquito files showing the Gee layout. From memory it came via John Adams with his notes pencilled in the margin.

It shows the central unit as being the IFF unit.

 

 

Some further notes from my files from an earlier discussion on this site regarding these same questions has the following:

 

48 of the earliest FB.VIs produced were fitted with T.1154B and R.1155 radio kit. In these a/c the transmitter and receiver units were mounted on the wing decking in the rear of the cockpit as depicted by most (all?) of the FB.VI kits, i.e. transmitter mounted centrally right at the back, and the receiver mounted sideways next to the observer's seat.

Later aircraft were fitted with the same R.1155 receiver but the T.1143 transmitter instead. In those a/c the R.1155 was mounted centrally on the wing decking in the rear of the cockpit (where the T.1154 was in the early a/c) and the T.1143 mounted back in the fuselage just aft of bulkhead 4. These a/c were also fitted with GEE Mk.II (A.R.I. 5083), the receiver for which was mounted on the port side of the wing decking (where the R.1155 was in the early a/c) and the indicator unit behind the pilot's seat.

 

 

[Crimea River]

On 8/31/2019 at 12:08 PM, Jonny said:

Folks,

 

Do, please, look at the material that Work in Progress provided (Post 7).

 

That material refers to R1355, not R1155.  I’m not sure what the physical difference between the 2 receivers was, but if the equipment numbers changed there must have been some, and probably significant ones, too.

 

Please be aware that the Wikipedia photos are of equipment displayed in a museum, not of anything actually installed in a Mosquito.  I rather think that the photos might be of radar equipment at the RAF Neatishead museum, in the UK.  When I've time I’ll look up the snaps I took at Neatishead some time ago.

 

Somewhere, in the dim & distant past, I seem to recall seeing a photo of a Mosquito cockpit with the GEE display unit installed immediately behind the pilot’s seat, angled so the Navogator could see and use it.  Behind that were the boxes associated with normal radio equipment.  God only knows where, or of what, the photo was of!  Sorry.

 

Hope this helps,

 

Jonny

 

 

R1355 is the Gee Receiver unit. R1155 was was the radio receiver, usually coupled with the T1154 Transmitter. Different beast altogether.

 

This is the pic you might be thinking of:

 

 

Or this:

 

 

Both show the Gee receiver, R1355, on the wing shelf behind the Gee indicator unit mounted on an angle behind the pilot's seat. There is absolutely no question about this arrangement, and I will be modelling these units as shown. There is a third major Gee component, the Control Panel (another box really), which, according to the AP, is mounted in the bowels of the fuselage behind bulkhead 4 (see diagram in Post #1, box entitled "Control Unit"). Ongoing discussion in the link I provided in post #8 suggests the possibility that, at some point, the control panel was moved up front next to the R1355 unit.

47 minutes ago, Pete M. said:

And just to confuse this question further, below is a sketch I have in my Mosquito files showing the Gee layout. From memory it came via John Adams with his notes pencilled in the margin.

It shows the central unit as being the IFF unit.

 

 

Some further notes from my files from an earlier discussion on this site regarding these same questions has the following:

 

48 of the earliest FB.VIs produced were fitted with T.1154B and R.1155 radio kit. In these a/c the transmitter and receiver units were mounted on the wing decking in the rear of the cockpit as depicted by most (all?) of the FB.VI kits, i.e. transmitter mounted centrally right at the back, and the receiver mounted sideways next to the observer's seat.

Later aircraft were fitted with the same R.1155 receiver but the T.1143 transmitter instead. In those a/c the R.1155 was mounted centrally on the wing decking in the rear of the cockpit (where the T.1154 was in the early a/c) and the T.1143 mounted back in the fuselage just aft of bulkhead 4. These a/c were also fitted with GEE Mk.II (A.R.I. 5083), the receiver for which was mounted on the port side of the wing decking (where the R.1155 was in the early a/c) and the indicator unit behind the pilot's seat.

 

 

Thank-you Pete. I received that sketch from @tango98 as well and the suggestion here is that the IFF Transmitter/Receiver is mounted next to the Gee receiver where, perhaps previously, the R1155 radio receiver was mounted. I have conflicting info on this. Whereas that sketch shows the IFF Tx/Rx in the cockpit, my copy of the Mosquito Explored DVD has this unit mounted in behind bulkhead 4, along with the TR1143 radio unit.

 

Thank-you for confirming that the R1155 was mounted on the wing shelf as stated in the AP and quoted in my post #1. I can only assume that as the war progressed, the R1155 unit was deleted or moved somewhere else and that the resulting space on the wing shelf became the domain of either the Gee Control Panel or the IFF Tx/Rx.n It's worth noting that the box mounted on the canopy rail in my first picture above is the switching unit associated with the IFF. It's se here mounted in the same location that the AP shows the Gee switch panel (see figure 7 in my first post).

 

I remain puzzled over the use of the R1155 unit without its usual T1154 mate and would love to hear the fate of it int he Mosquito over time. The three questions I posed in post #1 remain unanswered I'm afraid.

 

 

 

Edited September 2, 2019 by Crimea River

[Crimea River]

Yeah, I know, this thread has died but I wanted to share with you all what to me was a discovery. Apparently, the absence of a whip antenna in Mosquito photos doesn't necessarily mean that Gee was not carried. Take a close look at the ARI 5083 diagram in the original post. A closeup is below:

 

 

It would seem that the Mosquito's wooden construction enabled the Gee antenna to be carried internally. Comments welcome!

[Pete M.]

Makes sense instead of having a bloody great 41" whip aerial hanging out in the slipstream! Great catch.

 

Cheers,

Pete M.

[Anthony in NZ]

18 hours ago, Crimea River said:

Yeah, I know, this thread has died but I wanted to share with you all what to me was a discovery. Apparently, the absence of a whip antenna in Mosquito photos doesn't necessarily mean that Gee was not carried. Take a close look at the ARI 5083 diagram in the original post. A closeup is below:

 

 

It would seem that the Mosquito's wooden construction enabled the Gee antenna to be carried internally. Comments welcome!

Yes we believe HR339 had this internal aerial set up... Hey Pete, that's a great little drawing!

 

Love these discussions

Edited January 20, 2020 by Anthony in NZ