GB-43 1/48 Mosquito FB.VI - Aces' Aircraft of all Eras

Great Info.

In the first pic, what appears to be the Gee 'switchbox' thingy can be seen on the port side cockpit glazing (there seem to be different styles of this 'box')
In the last pic, if there was an antenna mast, it would be visible at this angle, so probably the internal VHF antenna.
Just to confuse things further, the cutaway below, from the Hayne's manual, is supposed to be a B.XVI, although I think there are some minor inaccuracies (canopy, for example)
The items shown as 56 and 57 are described as "ARI - 5083 Receiver" and " IFF Transmitter / Receiver" respectively. The ARI - 5083 is definitely the Gee R/F unit, but I have doubts about the identity of the IFF T/R, as I think this should be the radio remote for the TR 1143 transmitter / receiver in the aft fuselage, shown and identified as such, along with the internal antenna, on the rest of the cutaway drawing.
Whilst not directly related to the problem of identifying the radio fit, I finally located the two PDFs posted below, which are the Gee and Gee Mk,II manuals, and these show the various 'boxes' in detail.

Thanks once again Terry. There is consistency across many documents about the placement of the the Gee (A.R.I. 5083) Indicator and receiver behind the pilot seat so that much is certain. The control box for the Gee is almost certainly carried within the depths of the fuselage. Less certain is the presence of a third major box in the cockpit on the center of the wing deck. There appear to be 3 choices:

1) The manual calls out the R1155 unit and I have already decided to eliminate that choice because of the lack of a mast in the reference pics.
2) The box in your red bracket in the previous post, what you call the "radio remote" though I have not yet been able to identify what specifically this one is.
3) The IFF receiver. Now, though you posted the above cutaway with some trepidation that it may add confusion, the possibility of the IFF receiver being there is borne up by the note I received from Dave Wadman. He told me in private correspondence that friends of his did some research through files at Kew and found that the IFF Mk III receiver was in fact mounted there.

I have more info on this that I continue to investigate but am short of time at the moment. Perhaps I can expand later.

Sounds good Andy, and that box may well be the IFF receiver, as I think I may have seen it somewhere, either in a photo or film footage.
The box I call the radio remote (shown in the pic in red bracket) is the slightly puzzling one, as again I've seen it mentioned somewhere, and seen it included in some other model builds, but have not been able to find it's identity number, unless it's one of the SCR 522 series, which I doubt, as this was an American radio.
Anyway, with the TR 1143 back in the fuselage, and no 1155 on the 'shelf', there was certainly some other 'box' alongside the ARI-5083 receiver !
I wonder of the Duxford Radio Society could shed any light on this ?

Done a bit more digging, and it looks like that as yet unidentified box is the IFF unit.
The TR 1143 radio transmitter receiver in the aft fuselage was operated by the remote channel selector, on pre-set 'crystal' channels, the same type used in, eg, the Spitfire.
This was situated down by the pilot's left knee.
The I.F.F. switch and destruct were on the top of the console on the starboard side of the cockpit - second from the aft end, of the row of switches above the fuel management panel.
The I.F.F. controller, as we know, was on the port canopy rail, and the differences in appearance are related to the type, eg MkII etc, and origin, i.e. British or American manufacture, the latter being a 'licensed' British operating design, but with external differences presumably to do with manufacturing methods / practices etc.
Shown below are the radio remote channel selector, it's location on my model of the FB VI (red placard on angled, black box at front edge of pilot's seat), and the American produced I.F.F. transmitter / receiver Mk.III, along with its control unit, as mounted on the canopy frame.

Further to the info in Post #67, I've now remembered where I found the info regarding the radio, the type I moulded in resin, based on what was seen in the resin set shown earlier in red brackets, and other info in a book on modelling the Mosquito, which I have yet to discover where the hell I've hidden it, plus, from memory, photos found on the net and elsewhere.
The cutaway and key below are from my copy of "The Aircraft of 100 Group", by Martin Streetly, and show the radio 'box' ,marked 'u'' (lower case type) as the SCR 724MF radio installation. Note, however, that this is the NF 30 variant used by 100 Group, although I'm fairly sure that I've seen this in the FB.VI too.
Note that the Gee whip antenna is shown immediately aft of the canopy, whereas photos show it just inside the rear of the canopy, on the port side. This whip was 40 inches in length.
The same book also has a similar cutaway for the ASH equipped FB.VI, with what appears to be a similar radio fit, although not identified, but also shows both the 1143 and 1155 in the rear fuselage !
Unless evidence can be found to the contrary, it's probably acceptable to model either of these variations, which do look similar, and when viewed through the canopy, would pass for either type.

Lots to digest Terry and thanks for your continued digging. I'll be away all day driving Tim up to Edmonton where he starts his master's degree in psychology and won't be back til late tonight. I hope to swing by on the way and check on our Hurricane restoration as well. I'll look at your posts when I have more time tomorrow.

No problem Andy, and have a safe trip.
I'm not sure about the mention of the SCR724 radio as this may be a typo. Reading further in "Aircraft of 100 Group", in the section on electronics fit, under the part dealing with radios, the NF.30 is shown as being fitted with the SCR274 medium frequency radio (as used in Canadian Lancasters)
I've found info and photos on that unit, but nothing on the SCR 724.
I eventually found the Mosquito modelling book - I'd put it aside as it got severe water damage when I had that flood from the header tank a while, back.
The book is the Osprey "Modelling the De Havilland Mosquito", by master model maker Roy Sutherland, who creates the masters for 'Barracuda' and other companies, as well as model work in the film industry. In the book, he illustrates a conversion to a NF.XIX, using the Tamiya 1/48th kit for the NF. XIII / XVI, and the photos below show the kit parts for the radio shelf, along with his captions.
Perhaps not the strongest of references (although I based my FB.VI on this), but at least shows what I've been trying to find.
Considering the info to date, with the transmitter and receiver in the rear fuselage, I now think that the IFF unit should be on the shelf, alongside the Gee R/F unit, but for the detail that can actually be seen through the canopy, the set-up shown below would probably be acceptable, and, checking it against the pic of the IFF unit posted earlier, the Tamiya part is very possibly the IFF unit anyway, with the connectors and leads fitted, as the SCR274 has a very different front panel, and a narrower case.

Certainly the early FB.VI had the 1133 / 1155 on the shelf, as provided in most kits, but these were replaced by the later fit, as mentioned throughout this thread so far.
Earlier aircraft would be, and were up-dated, which would account for pics showing your aircraft with the mast, and then without.

Thanks again Terry. I have that Aircraft of 100 Group book as well. I dismissed the NF 30 cutaway initially as it was a much later mark, notwithstanding that radio fit-outs probably evolved in the field even on older marks, including FB VI's. Interestingly, that same book states, on page 137, that the standard radio fit-out on FB VI's was "one TR 1143 and one R1155", the same info I was struggling with to start off this whole discussion.

The TR 1143 equipment, including the switch box, is not an issue; the switch box is included with the Eduard detail set and the transmitter/receiver is located within the bowels of the fuselage and well out of sight.

I'm still wrestling with the mystery box/boxes and am confronted with some conflicting info that needs some quiet hours (and patience on my part) to go through. A bit busy now though. As you know, I'm not one to just throw stuff in my model without being able to rationalize the decision but it may come to that yet!

In the meantime, here's the scratch built Gee Indicator, finished a couple of days ago and awaiting paint. Connecting wires yet to be attached to the front.

Nice work on the Gee indicator. You probably know already, but there were two rows of cooling holes on the side walls of the case, but these can't be seen once installed in the Mossie cockpit.
I had the same frustration when trying to finalise the fit of equipment in my models, and to add further to the confusion, I've looked through the Gee Mk.II manual, and found the drawing shown below. This now begs the question, is that 'mystery box' the I.F.F. or is it the Gee control panel ?!!!

Might be making a little more headway.
I remembered the photos I had of 'Gee', and particularly the Lancaster Nav station replica at Duxford, which showed the main components, so checked these, and compared them to a schematic of the Nav installations in the Lanc, and they match, and correspond to the info in the Gee manual describing the components and installation which, with minor variations, would be the same in different aircraft types.
I now believe that there's a very good chance that the second 'box' is actually the Gee control panel, as shown in the drawing posted previously.
The pics below show (Pic 1) the three main components for Gee (but not including the switch panel), these being the indicator, R/F unit and control panel, and (Pic 2) the same installation in the Lanc, beneath the map table (yellow arrows), the other items being power units, and the associated items for the H2s etc..
There are some differences in the layout of terminal connections etc, which I'm fairly sure is related to which Mark/ Model is shown.
Pic 3 shows the switch panel mounted on the canopy side in a Mosquito..
How does this compare with the info you've received so far ?

Thanks all. Terry, your help is very much appreciated.

First off, I'm aware of the cooling holes but decided not to bother because, as you said, they won't be seen because of the close proximity of the pilot's seat back and the wing spar.

As to the mystery box, I suppose it's possible that, at some point, the control panel/unit moved from it's specified position behind bulkhead 4 to the wing shelf but I had assumed up to now that it remained there. See the figure from the manual below.



I had always associated the control panel with the control unit. Note also the location and shape of the switch panel just above the indicator unit. This panel, part of the Gee system, shows up in the schematic drawing in the manual above (you can just see part of it at bottom left above). It is also described in the manual, in words, as being mounted above the indicator unit.

The information I received from Dave Wadman suggests what you said earlier, that the "mystery box" is the IFF T/R. He included the same picture as you did in post #67 which shows the T/R and its associated switch box. To my eye, the switch box in the picture in post 67 is the same as the one mounted above the indicator unit in the last picture of your post immediately above. So that would mean that the Gee Switch box was moved and may have changed in style at some point (if the drawing you included in post 67 purports to represent the various parts realistically, then "Switchbox Type B" looks nothing like the one I posted above).

The reason I'm not yet convinced about the mystery box being the IFF T/R stems from 2 concerns:

1) the size of this box is quoted as 12" high x 12" long x 9" deep with the face showing the letter "D" in your picture pointing toward starboard. The associated switch box is stated as being on the starboard wall next to the Observer, not, as suggested in your picture, mounted on the port canopy rail.
2) I have a copy of the DVD "Mosquito Explored" which shows the same IFF T/R unit mounted out of sight in the mid-fuselage near the TR 1143 unit in Mosquito NF II s/n HJ711 (that's the same specimen represented by your pic of the Gee system immediately above).

The Mosquito explored DVD also shows this:



It goes on to identify that the Gee junction box is at left (makes sense - shown as such in the manual diagram above) and the Gee receiver being in the center (WRONG!!!!). The box in the center is clearly NOT the Gee receiver; that's the unit at right. What's more, this is the same aircraft as in your picture above, an NF II, but I suspect it was taken at a time when the aircraft was part way through restoration. Note that the Gee receiver is mounted on wooden blocks and there is no interconnecting wiring anywhere. Now, if you look closely at the "mystery box" and compare it to the schematic diagram you posted and the unit under your right yellow arrow, the connector configuration and grab handles do strongly suggest that the box is, in fact, the Gee Control Panel (Unit).

So, it would seem that the NF II might have had the entire 3-box Gee set-up in the cockpit and the IFF T/R housed in the mid-fuselage with it's switch box up front above the Gee Indicator if we can believe the pictures and description in the Mosquito Explored DVD. However, the error in identification of the units doesn't help with credibility here.

I'm going to let all this marinate for a bit yet and make a decision soon.

Thanks again Terry.

Wow!! Lots of info. Great mods Andy

The set-up shown in the last pic is what I would expect to see, with the Gee control unit (Control panel in the diagram) alongside the Gee R/F unit. The location of the Gee power switch (Switch box Type B in the diagram), I'm not certain of, but the IFF master switch and destruct unit switches are mounted on the starboard side console (shown as JBB in the diagram), at the rear end, as shown in the FB.VI Pilot's Notes, and in cockpit photos , of other Marks, from the relevant Pilot's Notes.
It's possible that the Gee power switch was also located here - the Pilot's Notes make no mention of Gee.
The switch panel on the port side, shown in the diagram and my photo, is the IFF control switch panel, and mounted in the cockpit would suggest, to me at least, that the IFF unit itself was mounted in the fuselage, which would make sense, especially as it was fitted with an explosive charge, and this unit would be connected to the antenna, also in the rear fuselage. It doesn't seem to make sense that such a bulky unit, with no direct controls attached, would be located where space is already limited, in the cockpit, when other equipment is needed there.
The Gee antenna was, as mentioned earlier, the 40 inch whip through the rear of the canopy, just off center to port.
EDIT: Forgot to mention and add the photo, with the IFF control switch panel clearly visible under the canopy.