My Second Radialva Groom Restore

[pwdrive]

Hi Gary, I have never come across staggered IF's for standard AM either, but I thought I would ask to make sure. Removing slugs can be a pain as you know but in the main they normally give up and come out or at least loosen up enough for alignment purposes. My own experiences tally up with yours, the slot has to be cleaned out real good and the tool that is used to fit in the slot needs to be an exact fit to the profile of the slot, I find that initially screwing them in rather than trying to unscrew them is a good option, if all goes well it will reveal a turn or two of clean thread in the former then you can follow and clean up from that with an angled pointed tool to scrape the gunked up part of the thread out. I did an R1155 a while back, I did all the slugs in rf/osc coils but one had snapped in one of the IF's, I swept the generator through it and it was about 500c/s out so I realigned the other IF's and the BFO to that with good results.
I remember doing loads of tv's in the 60's the hex slug ruled then, they really were a pain, a lot of manufactures used polystyrtene formers which due to the heat in the tv tended to shrink on the slug, the only option was to break or drill them out.

Lawrence.

[Radio Fixer]

Good tips Lawrence... Its always worth taking time to clean out the slots and find or make a good fitting tool. Its the same with screws: I cant abide chipped or mauled ones and nowdays screwdriver sets are so cheap from the likes of Aldi. Means we can have plenty and even touch one up on a grind stone to be a perfect fit.

As you say screwing the slug in a turn or so first is often a good option, then rake out any wax etc behind it.

If I was John I would, with a really good fitting tool try that first, without any solvent. Of course you need a certain feel for it, dont put so much force on you break the slug. Reasonable and from there if needed move to some solvent.

Gary

[Geaney]

Hi Guys,

The cap values I mentioned are totals.

The attached clip will hopefully make it clearer ( I know not everyone on here are big fans of YouTube so I hesitate to post links but this one should help). You have to scoot up to the second half of the clip to see the part where I'm messing around with IF transformers.

http://www.youtube.com/watch?v=7JNTjEXAZSY

Cheers, John

[Radio Fixer]

Hi John

Watched the vid with interest. Is the new dial a silk screen job? Interesting one to do artwork for in Corel Draw.

Now to the IFs: a neat small scope there with the direct freq readout. I tried your way of doing a measurement on an IF and compared it to mine and of course if the tuned cct will resonate they have to give the same reasult.

Actually they are identical except I have a 120K feed from the osc and you have the 10M of the scope probe (I assume it is a 10M probe?) in circuit. In mine it is easy to see that the 10M and the 10pF of the probe is across the tuned cct. It is in your case too as Ro (Rout) of the osc will be low.

   

Dont forget to clean away the clear coat on the chassis for earthing tags or use toothed washers under them. Another way is it to put on solder tags, for earth points first, and mask the solder part before spraying. And if its is to be a bolted down tag, on a strip, a nut bolt and washer of appropiate size, can be fitted before spraying and then discarded during the build (this often gives a neater job than trying to remove clear coat after).

Gary

[Geaney]

Hi John

Is the new dial a silk screen job? Interesting one to do artwork for in Corel Draw.

Dont forget to clean away the clear coat on the chassis for earthing tags or use toothed washers under them.

Gary

Hi Gary, Ben Dijkman in Holland is doing the dials for me and I assume it is the original silk screen process. I've ordered about five dials since I can use two and I'm sure I'll find homes for the others.
I masked all the areas that have earth points before I clear coated so hopefully all will be well in that regard.

Thanks for the picture re IF checking - a real example of where a picture is worth a thousand words!

Pretty soon I can get down to the electronics side of the project.

Cheers, John

[Geaney]

Well it's been a while but my replica dial for the Radialva arrived this morning. Ben does excellent work. Now I've just got to find time to get this project back on the bench. It might be a while since the Minerva and the Eiko 950A have lots to get done on them first.

Cheers, John

[Mark R]

How good does that dial glass look! splendid.

cheers Mark

[Radio Fixer]

Yeah! beautiful. Could be one of these, new to me anyway, flat bed printers. Have the first dial done for a Marconi 561 (great radio) by Radio Daze this way.

Once I get some more pics I will advertise it on here and VRAT and see who wants one. To me its WOW! and is going to bring my radio alive. I have assisted in this project, with a new BVWS member (he did all the liason work) who is restoring a 561 to high standard (my sorta guy!). As usual price comes down if more are wanted. Completely non-profit making, cost + shipping only.

Gary

[pwdrive]

Hi John, only just noticed the new dial, it looks a first class job, well done that man.

Lawrence.

[Geaney]

Well here I am just one year since the last post on this project. I dusted it off a week or so back and started to rewire. I'm now at the stage where I need to make the coils before I can go further. Hopefully it won't be a year before I get that done!

Cheers, John