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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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8th May 2023, 10:25 pm | #1 |
Tetrode
Join Date: Jun 2008
Location: Stratford upon Avon, Warwickshire, UK.
Posts: 80
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R1155 transformer core stuck
Hi,
Can anyone suggest a way to soften the locking compound used on this core adjuster which is Bakelite in a Bakelite surround. I have tried switch cleaner, very thin oil, acetone and soaking in boiling water but it has not moved 0.01mm. All suggestions gratefully received.
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Best wishes, Geoffrey. |
9th May 2023, 1:25 am | #2 |
Heptode
Join Date: Oct 2005
Location: Olympia, Washington, USA.
Posts: 664
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Re: R1155 transformer core stuck
I had a problem decades ago with 2 variable transformers not adjusting. Turned out the lube they used on the Bakelite insulating rod swelled it up. I finally used a punch and light hammer to free it. Sanded it down to correct diameter and cleaned all the old lube off and used silicone grease for the lube.
I suspect this may be the case on your core, or the core was sealed in by an epoxy. If it's a "do or die" you might try a small pencil torch to heat it up. or the hammer & punch method. Risk is it could cause damage to the unit. Loctite corp may make a solvent to remove thread lock and that might be worth a try also. |
9th May 2023, 8:03 am | #3 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,935
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Re: R1155 transformer core stuck
Does it really need adjusting ?
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G8JET BVWS Archivist and Member V.M.A.R.S |
10th May 2023, 11:24 am | #4 |
Tetrode
Join Date: Jun 2008
Location: Stratford upon Avon, Warwickshire, UK.
Posts: 80
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Re: R1155 transformer core stuck
Hi to FrankB and HamishBoxer,
Thank you for your replies, I was hoping that someone had had this problem before and had found a suitable solvent, it would seem not. I do need to adjust the core in order to balance the DF loop. Best wishes, Geoffrey. |
10th May 2023, 11:51 am | #5 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,935
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Re: R1155 transformer core stuck
Understood Geoffrey.
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G8JET BVWS Archivist and Member V.M.A.R.S |
11th May 2023, 10:42 am | #6 |
Hexode
Join Date: Mar 2011
Location: Wilstead, Bedfordshire, UK.
Posts: 367
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Re: R1155 transformer core stuck
Hi
I have several R1155s, where is this capacitor located, I do not recognise it at all, but knowing how the AM wanted everything on these receivers locked tight they may have used Shellack (not sure if I have spelt that right) if so Methylated Spirits may work. Let me know its location and I will look and see if I have one. Regards Bill |
11th May 2023, 1:11 pm | #7 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
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Re: R1155 transformer core stuck
I don't think capacitors have been mentioned.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
11th May 2023, 4:52 pm | #8 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: R1155 transformer core stuck
Just for info for anyone that's interested, the DF Loop coils in the info I'm looking at in AP1186 Vol. 1 (Revised) are L4, L5 & L6, their top side chassis layout locations are Db, Da & Ca respectively.
Their trimmer capacitors are C57, C58 & C59 respectively, their bottom side chassis layout locations are Ah (C57 & C58) and Ag (C59) Lawrence. |
22nd May 2023, 2:55 pm | #9 |
Tetrode
Join Date: Jun 2008
Location: Stratford upon Avon, Warwickshire, UK.
Posts: 80
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Re: R1155 transformer core stuck
Dear Bill, Graham and Lawrence,
Thank you for your replies. It is one of the DF coil adjusters that is stuck solid - L4 but L5 is similar. If I come up with a solution I will post it. Best wishes, Geoffrey. |
22nd May 2023, 11:33 pm | #10 |
Hexode
Join Date: Mar 2011
Location: Wilstead, Bedfordshire, UK.
Posts: 367
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Re: R1155 transformer core stuck
Hi My mistake where I got "capacitor" from I don't know.
Where in the r1155 is this part fitted, I have several r1155s and if possible I can remove it Regards Bill |