10D/16555 plug-in oscillator tuning unit - identification? - UK Vintage Radio Repair and Restoration Discussion Forum

m0cemdave · 3rd Feb 2017, 5:42 pm

This is a plug-in module containing tuned tank and coupling coils for a VHF oscillator. It looks like it's from a piece of WW2-era equipment.

The centre tapped tuning coil is split, with a centre tapped coupling coil in the middle. The tuning capacitor is labelled 10C/16549 and is a dual gang type, rather then the butterfly style normally found in later designs of VHF equipment.

The terminal panel is stamped with the number 10AR/517 and it also carries the number AY223 in the ceramic plate. There are 6 sockets, all 4mm bore.
The top three terminals are the coupling coil, with the centre tap connected via a resistor that measures 3140 ohms and is marked (assuming body-tip-spot) 2k7.
The lower terminals are the tuning coil. One end is connected via a 15pF N750K ceramic capacitor.

The sloping front panel is cast metal and is fitted with a slow motion drive, scaled 0-100, with a locking clamp. A rough check with a dip meter indicates a tuning range of around 80 - 160 MHz.

A hinged handle allows the unit to be extracted (from whatever it fits into) by pulling it forward, and there are two knurled screws to lock it in place when fitted.

The various military stores numbers don't come up in a Google search, so does anyone know what this is a part of?

p.s.
I should perhaps point out that it has no association with the mystery valves in my other message.

trh01uk · 3rd Feb 2017, 6:13 pm

Dave,

my total guess is that this unit is part of the T1131, VHF ground transmitter. But that is total guesswork.

What you need is a copy of AP1086 section 10C. If you search the web you will find the copy that Chris Cooper did a while ago. Alternatively my friend Andy has access to that file and others, and he may be able to find it listed.

I'd look it up for you - but I'm on a GWR train using their wi-fi - and its struggling to even load this page up - let alone download large files.....

Richard

M0FYA Andy · 3rd Feb 2017, 8:44 pm

Unfortunately I've drawn a blank with 10D/16555 and 10C/16549.
I've had a quick shufti through the chapter on the T1131 in my copy of A.P.1186A, and can't spot anything like this unit, but bear with me, I'll have a more careful look through.
Andy

3rd Feb 2017, 5:42 pm	#1
m0cemdave Octode Join Date: Feb 2009 Location: Bletchley, Buckinghamshire, UK. Posts: 1,218	10D/16555 plug-in oscillator tuning unit - identification? This is a plug-in module containing tuned tank and coupling coils for a VHF oscillator. It looks like it's from a piece of WW2-era equipment. The centre tapped tuning coil is split, with a centre tapped coupling coil in the middle. The tuning capacitor is labelled 10C/16549 and is a dual gang type, rather then the butterfly style normally found in later designs of VHF equipment. The terminal panel is stamped with the number 10AR/517 and it also carries the number AY223 in the ceramic plate. There are 6 sockets, all 4mm bore. The top three terminals are the coupling coil, with the centre tap connected via a resistor that measures 3140 ohms and is marked (assuming body-tip-spot) 2k7. The lower terminals are the tuning coil. One end is connected via a 15pF N750K ceramic capacitor. The sloping front panel is cast metal and is fitted with a slow motion drive, scaled 0-100, with a locking clamp. A rough check with a dip meter indicates a tuning range of around 80 - 160 MHz. A hinged handle allows the unit to be extracted (from whatever it fits into) by pulling it forward, and there are two knurled screws to lock it in place when fitted. The various military stores numbers don't come up in a Google search, so does anyone know what this is a part of? p.s. I should perhaps point out that it has no association with the mystery valves in my other message. Attached Thumbnails

3rd Feb 2017, 6:13 pm	#2
trh01uk Octode Join Date: Nov 2010 Location: Ross-on-Wye, Herefordshire, UK. Posts: 1,652	Re: 10D/16555 plug-in oscillator tuning unit - identification? Dave, my total guess is that this unit is part of the T1131, VHF ground transmitter. But that is total guesswork. What you need is a copy of AP1086 section 10C. If you search the web you will find the copy that Chris Cooper did a while ago. Alternatively my friend Andy has access to that file and others, and he may be able to find it listed. I'd look it up for you - but I'm on a GWR train using their wi-fi - and its struggling to even load this page up - let alone download large files..... Richard

3rd Feb 2017, 8:44 pm	#3
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: 10D/16555 plug-in oscillator tuning unit - identification? Unfortunately I've drawn a blank with 10D/16555 and 10C/16549. I've had a quick shufti through the chapter on the T1131 in my copy of A.P.1186A, and can't spot anything like this unit, but bear with me, I'll have a more careful look through. Andy