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-   -   Heathkit RG-1 (https://www.vintage-radio.net/forum/showthread.php?t=178791)

Johnbarn 10th Apr 2021 11:05 pm

Heathkit RG-1
 
I have been given one of these communications receivers which was apparently working til stored away 30 years ago. After the usual tests with lamp limiter and checking internally, all looked well and the set came to life, but only on MW. All other positions of the 6-way wave change switch were dead. Even on MW the switch was making only intermittent contact. I cleaned the switch wafers with contact cleaner, operated it a few times and could get a few of the other switch positions to work intermittently. However the switch was very unreliable and I noticed that centre of one of the wafers was out of line with its contact bank. In fact the centre of that switch bank, the one furthest from the knob, was sitting at an angle and not held to the switch shaft at all. Two of the tiny copper contacts were loose inside. As there are a further two switch wafers on this switch I can see no easy way to mend it and wondered if anyone had a scrap set from which I could salvage the switch. The rest of the set looks in good condition and it would be good to get it going again.

Ed_Dinning 11th Apr 2021 8:06 am

Re: Heathkit RG-1
 
Hi John, could be hen's teeth I'm afraid, but if you can rebuild the assembly, which would be a bit fiddly, you are in with a chance.
If you can post pictures of the assembly there is a good chance members may have prts for the mech and wafers in their junk boxes

Ed

Johnbarn 11th Apr 2021 11:41 am

Re: Heathkit RG-1
 
3 Attachment(s)
Thank you for that, I guessed it was a long shot but here are three photos showing the disintegrated switch wafer, just in case. As you can see the rest of the radio is worth saving.

dodgy-dxer 11th Apr 2021 12:39 pm

Re: Heathkit RG-1
 
John

You might need to widen your search and you could try the "heathkit-radios" group on groups.io?

Fred

Pamphonica 11th Apr 2021 12:52 pm

Re: Heathkit RG-1
 
I have a huge box of Makaswitch parts. If you can specify the wafer configuration (eg 2P6W - two pole six way) etc I'll have a look for some spare wafers. Also, it would help if you can get a micrometer in there and chack the diameter of the shaft and the width across the "flat" section.

Ed_Dinning 11th Apr 2021 12:59 pm

Re: Heathkit RG-1
 
Hi John, it should not be too difficult as it is only the rear wafer.
Take copious notes and pictures and the carefully desolder the rear wafer and pull the switch mechanism forward to remove the wafer and post details here. I looks a common enough type for someone to have one in their parts box

Ed

Johnbarn 11th Apr 2021 2:43 pm

Re: Heathkit RG-1
 
Thanks everybody, I’ll do the dismantling this week and report back, J

Restoration73 11th Apr 2021 3:29 pm

Re: Heathkit RG-1
 
Note the tuned circuit "box" was pre-assembled. The neat cable lacing suggests
this was a factory built set. It worth stating that the wafers were made in both make-before-break and break-before-make versions.

Ed_Dinning 11th Apr 2021 3:50 pm

Re: Heathkit RG-1
 
Also note that some of the wafers may well have shorting contacts on the rear of the wafer so the all coils other than the one in use are shorted to ground

Ed

Johnbarn 11th Apr 2021 9:08 pm

Re: Heathkit RG-1
 
Hmm, this project is sounding more and more tricky! But I’ll press on, one crisis at a time, thanks everyone.

m0cemdave 11th Apr 2021 9:35 pm

Re: Heathkit RG-1
 
If you remove those two nuts and washers, the switch bank should pull off the spindle enabling both sides to be photographed for reference when reassembling.
You can then unsolder it and take further pictures of it laid out on the bench.
Add the dimensions (these switches came in at least two sizes), and post here. Somebody is very likely to have a matching wafer.

Peter F4VSA 11th Apr 2021 10:01 pm

Re: Heathkit RG-1
 
The Heathkit RG1 incorporates the STC/Electroniques prealigned front end. Secondhand examples do come up for sale sometimes. I do have an RG1 and some componemts, I'll have a look tomorrow to see if I have any spare switch wafers.

Peter

Peter F4VSA 12th Apr 2021 6:26 pm

Re: Heathkit RG-1
 
2 Attachment(s)
Hi, please see the two attached pictures. Happy to post a couple to you if you think that they will work.

Peter

Johnbarn 12th Apr 2021 7:04 pm

Re: Heathkit RG-1
 
4 Attachment(s)
Thank you everyone. I have taken the switch off and measurements are; spindle across two flats 4.88 mm, spindle dia 6.32 mm, switch wafer dia 28.72 mm. Three photos attached showing the body plus two wafers and the two contacts from somewhere inside the switch. Donít know where they were meant to be before the thing disintegrated. Also one photo of the Heathkit circuit diagram which is fairly unhelpful since it shows none of the actual switching arrangements so I cannot tell which switch contacts were made in any of the six positions. Looking at the photo of Peterís switches sadly I donít think any of them will do but thank you for the offer, I appreciate it. I suspect that an identical unit is the only answer.

Pamphonica 12th Apr 2021 7:21 pm

Re: Heathkit RG-1
 
What's the spacing of the mounting holes?
Looks like a break-before-make.

Johnbarn 12th Apr 2021 7:32 pm

Re: Heathkit RG-1
 
Jeremy, hole spacing is 26.5mm.

Peter F4VSA 12th Apr 2021 8:16 pm

Re: Heathkit RG-1
 
1 Attachment(s)
Hi John, no problem. Please have a look at the attached pdf, it's the data sheet for your front end. The rf and mixer input swtches are break before make, all sections have a shorting contact, shorting all coils not in circuit.

Peter

Johnbarn 12th Apr 2021 8:32 pm

Re: Heathkit RG-1
 
Peter, on reflection a couple of questions re your switches. There are 14 terminals on mine but not evenly spaced. Reading from mounting hole to mounting hole on the top half 1,2 and 3 are set close together, the other 4 are equally spaced. Similarly for the lower half. Is that anything like either of the two lower switches shown in your picture?

Ed_Dinning 12th Apr 2021 8:45 pm

Re: Heathkit RG-1
 
The tag that is closely spaced between 2 others will be the wiper contact. There are 2 like this 180 deg apart
There does not seem to be earthing contacts on the picture posted by John, this simplifies finding a suitable wafer as this wafer does not earth unused contacts

As it is a 2P, 6W type the 2, small clips will be the linking contacts that perform the selection.

It looks very like the blue bodied Maka Switch that was supplied by RS

Ed

Peter F4VSA 12th Apr 2021 9:13 pm

Re: Heathkit RG-1
 
Quote:

Originally Posted by Johnbarn (Post 1363679)
Peter, on reflection a couple of questions re your switches. There are 14 terminals on mine but not evenly spaced. Reading from mounting hole to mounting hole on the top half 1,2 and 3 are set close together, the other 4 are equally spaced. Similarly for the lower half. Is that anything like either of the two lower switches shown in your picture?

Hi John, yes indeed I will send some better pictures tomorrow and the mounting hole spacing is 26.5mm. I'll also send a picture of my RG1 of the same area. The switches I have are almost certain to be from a similar receiver

Peter


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