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51J-4 Restoration #restore


Stewart Thorp
 

Hi I have a 51J-4 - I believe it is a 51J-4 as it has 3 mechanical filters, but it has no discernible markings that I can see.
Does this forum cover these units as well as the S-Line?  If not I apologize please point me in the right direction.  As far as I understand although this was essentially a military unit it also was used by some wealthy hams at the time?

The general condition of this is amazing from what I can tell - very clean and well looked after.
- C217 has been removed, but the capacitance has been added underneath chassis with modern electrolytics.
- C215 and C216 are still original and in place, am thinking I should test these, although I have been told these older electrolytics are incredible quality and can hold values even now?
-  C123 and L-122 are corroded as in pics I intend to clean these up and at least halt corrorsion.
- 2 iron slugs have come to pieces, but am very fortunate to have found all of the individual pieces, so I intend to epoxy these back together and all other slugs appear to still move freely, although I may have some cracks in others to epoxy where the iron core has expanded slightly.

Am I able to purchase a clear chart roll? although I am not sure if this is a good idea as to replace it would require a level of disassembly that I am not wanting.  I'd possibly rather leave it as is, advice pending.
Some ideas to help with cleaning the general sticky dust that seems to accumulate on these may be helpful - The S-Line seems far less tricky to get apart  - in particular the tuning cord assembly just looks like it was meant to be left alone.

I really like the fact that these radios were so far ahead of their time when released - the mechanical way of solving these complex challenges fascinates me.

Some pics attached for reference, and would be very keen to hear about what in particular to check capacitor wise - the micas may all be OK yet, I may spot check a few.

Thanks and 73s,
Stew Thorp
ZL2VA 


F6FER Roger - CCAE#016
 

Hello Stewart


On Tue, Dec 22, 2020 at 03:35 AM, Stewart Thorp wrote:
Does this forum cover these units as well as the S-Line?

Of course it does.
Any communication Collins equipment ( ham radio, military, aeronautics or broadcast ) is welcome, as long as it concerns receiving or transmitting over the airwaves.

I hope the owner or knower of a 51J-4 will help you.

Cheers and season greetings.

--

73 Roger - F6FER - CCAE#016


Stewart Thorp
 

Ok great!
Thanks Roger, 
That is great to gear as I have allsorts!

Some is not possible nor practical due to missing expensive or heavy parts not really available in New Zealand but other units like the 51J-4 are really close and are already in good shape.

Cheers!
Stew
ZL2VA 


On Wed, 23 Dec 2020, 12:39 AM F6FER Roger - CCAE#016 via groups.io, <f6fer=yahoo.fr@groups.io> wrote:
Hello Stewart

On Tue, Dec 22, 2020 at 03:35 AM, Stewart Thorp wrote:
Does this forum cover these units as well as the S-Line?

Of course it does.
Any communication Collins equipment ( ham radio, military, aeronautics or broadcast ) is welcome, as long as it concerns receiving or transmitting over the airwaves.

I hope the owner or knower of a 51J-4 will help you.

Cheers and season greetings.

--

73 Roger - F6FER - CCAE#016