Saba 530WL - total restoration.

[Piotrek J.]

Hello and welcome to my next renovation project. 
I'm sorry for writing in English, but it's still hard for me to write longer texts in German. 

For a quite some time I was looking for a missing Saba from a season 35/36 – model 530 or 531 (I'm missing 336, but it's not so needed). I noticed those are really hard to find. Around a month ago I saw an auction with very bad 530WL starting from around 0.25 Euro. Finally I won that auction for 10 Euro – but radio was missing loudspeaker, knobs, transformer and tubes. But even so... I picked up radio from seller who gave me also two bad  and partly dismantled chassis from 531WL and 335WL. 
I decided on rebuilding the radio as best as I can (I have quite some part collection from Saba radios) – seems like pointless work but I have a soft spot for models from that season – apparently very few people like them. 
First, two pictures from the auction:


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About Drehko – it's of course broken but I have a spare one from season 37/38 – they are virtually the same except they are actually in good contition. Brass belt from tuning mechanism is torn and zinc clutch was swollen, but otherwise mechanism is complete (belt tension screws are very important). 

First thing I did was to draw a more or less exact „map” of underside of the chassis – radio was repaired many times in the past, so I couldn't trust some of the connections.  Then I separated metal parts for galvanization and painting. As it was, additional chassis was in better condition than the original one. 

   

   

I also made a list of components in accordance with service manual – I have all necessary resistors but a few of capacitors are missing, tube sockets are all checked and replaced when it was neccessary, polished switching axle and washed all the contact sets. 

After a week I picked up parts from galvanization, meanwhile I painted chassis and its parts in silver very similar to original shade of paint. So it looks like parts straight from the factory.

   

And that is the state of radio now – in the coming days I should start putting it all together but I know it's a long way before radio would play again. 

As it is of course there are problems. Especially that I still miss some parts which are:

amperometer
loudspeaker
knobs
original mains trafo. 

I have similar transformer but I'm not sure if it's any good. I have loudspeaker but it's cone is cracked around the edges – those are the problems that maybe can be solved. 

But if someone has knobs and amperometer (can be broken, I will repair it), that would be great...



Best regards
Piotr

PS: Feel free to write in German.

PS: Now I noticed that the post is in the wrong category - could moderator move in to "vor 1945"?

[Juan1]

Hello Piotr
Please can you explain waht is the Ampermeter?
I am a little lost.

[Gasherbrum]

The Tuning Indicator. A former Magic Eye.

[Piotrek J.]

Ja, das ist Abstimmanzeige, Es sieht so aus (Bild von 335WL):
   

[DiRu †]

Und so wurde der 530WL in der Saison 1935/1936 beworben.

   


MfG DR

[Juan1]

Now it is a lot more clear.
A Ampermeter is a Ampermete.........clear.
I was thinking this Receiver has no tuning indicator, Because you look automatically for a indicator VALVE.
I did not see the indicator needle.
Exact replacement will be difficult. My be something similar? or need to be 100% original?

[Piotrek J.]

Hello, 
today a small update - I'm currently working on few projects, so the progress is not so fast. And it takes a while to complete all sorts of parts - screws, washers, good sockets etc. 
So during last few days I managed to finish mostly mechanical work on the chassis, with all the coils, sockets switches in place. I gathered all the necessary resistors and capacitors (still yet to be boiled in paraffin wax) and put together main capacitor.
I still need to make rubber parts needed for two-speed scale drive. If everything is in order, that should be my third working scale drive. It's quite simple comparing to the thing I'm working on now. 

By the way, somebody has any experience in tuning those Saba ZF filters? It seems that they are glued solid. All four 200cm capacitors are broken inside them so I will replace them, but then I should do a slight tuning of ZF...

So here are the pictures:

   

   

   

Best regards
Piotr

[olli0371]

Hi Piotr,

Can you Post a picture of the ZF Filters to show where it is glued ? I ask because at my 455wk I could very easy allign the filters after changing the parallel capacitors. And in case you can not get the cores loose you could install e.g. 180 pF parallel caps together with a small trimmer to allign the filters before breaking something.

Anyway - I like the idea of boiling the paper caps. I did this also for some radios and in many cases it works. Isolation resistance measured with high voltage is like new or high enough for the area where the cap is installed.

Oliver

[Juan1]

I know glued adjustment screws from Telefunken in the 50ies.
Really dificult to remove as you can not use Heat because the coil suport will suffer as well from deformation. (Red paint)
Please make a good picture, may be I have something in my spare part bin, that can replace the damaged one

As I can see, the temperatura outside is cold, and you stay working at home. GOOD option
Yesterday I lose the complete day because Wife wanted to go shoping... No time for Radios.

Last picture is a calculator, If I am not wrong.
I like this chalenge repairs. The satisfaction once it Works is great. More if you made parts by yourself.

If you send the pictures quick, I can take them to Poland and send them from Bydgoszcz next Thursday. In case I find something.

[Piotrek J.]

Hello,
thank you for your answers, about those ZF filters - they are complete and undamaged, but the capacitors are dead. Maybe I will try to press them hard, it seems they are mica capacitors with riveted ends sealed with tar. The cores of the coils are protected by paint, but I'm not sure what to use to remove that paint without destroying the coils. But it's the long way yet before radio would be turned on.

I have many radios with restored paper capacitors and they work without problems. I check them with 300V test voltage and they usually pass that test. Only downside is that the capacity is slightly lower. I haven't found a solution to restore electrolytic capacitors in paper tubes - they are usually so corroded that there's no chance of saving them.

I have many spare parts from various Saba radios (they are almost 1/4 of my collection) so I think I will experiment with ZF circuits.

Best regards
Piotr

[Juan1]

Yes I know this paper roll electrolytic´s.
I substitute them by changing the interior of the roll by axial 50 uF aluminum cans. Late CCCP production
I have plenty of them (same format as used by Telefunken Spain beginning the 50ies.

For the riveted Mica capacitors , may be you can remove the Tar with some light solvent (petrol).
Once they are clean you can ad some silver paint to recover the electrical contact.
( the one to repair damaged circuit boards)
Careful, as the rivets have contact to the silver surface only on one side. The other side is on a isolated island.
As this capacitors do not change the value with the years they should work fine once the contact is recovered.
May be a new Mika (with less capacity) plus small air capacitor trimmer will do the same job?

Please provide some pictures of the Filters and the capacitors to see if I have something for you.

Finally my trip to Poland was postponed by one week. Time to search for parts :-)

[Piotrek J.]

I will use new capacitors hidden inside original shell. I once tried to fill them with electrolyte taken from old metal capacitors (diluted with demineralised water), there was some capacity showing but corrosion was almost always too great to do anything. You would virtually have to roll up a new capactior. 

I will look into those mica capacitors, it would be nice to have as much original parts as possible. But still it won't be an original state which slightly saddens me. But there's not many of those models avaiable so I think it's worth it. 

Also thank you for your offer but as the filters go I have plenty of them. I have circuits from 531WL, two 446WLK and 335WL and complete chassis from 444GWLK (which I still keep in hopes that I can get housing with loudspeaker for it). I often buy Sabas for parts if they are in good price - sadly their prewar quality isn't the best - use of painted ungalvanised steel for chassis, that zinc parts which are cracked, very weak tube sockets which are prone to breaking (as other plastic materials) etc, etc... So if you are into Saba radios you just have to have some spares. 

Regards
Piotr

PS: Where you will be in Poland?