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A14 BCC30 vehicle adaptor, and WS29.


Martin Owen
 

Good afternoon all.


Does anyone have intimate knowledge of the inverter based vehicle adaptor for the A14 'manpack'?


The two 12 volt supplies connected in series as part of the 36v high power supply to the set are failed on mine.

Is a signal needed from the harness to enable them I wonder.

As you can guess, I do not have a ckt. diagram.

Any help appreciated.


Plus, I am looking for a variometer for the WS29, it looks like a WS19 one, but has a bulge on the side for

the motor drive.

Even a casing with no guts would be a start!


Thanks


Martin G4JSX.




Martin Owen 07802 982698, 01788 832324


Jacques_VE2JFE
 

Hello Martin,

Welcome to the group !

You are searching for a WS #29 variometer ?

Wow… I hope that you already know why they are excessively rare…

BTW, what are the other parts of the WS #29 set you already have ?

I also “collect” the serial numbers of those WS #29 units, as well as the ones of WS #19 and #52.

Only the WS #19 “World Inventory” is published by now (see: https://groups.io/g/wireless-set-no19/files/WS19,%20WS22,%20&%20WS62 )

The other lists will also be published, eventually.

Greetings from Montreal (where all the CDN #19s and #29 were made).

 

73, Jacques, VE2JFE


Martin Owen
 


Hello Jacques, thanks for the message about the WS29.


I have the main set, the B set and the psu.

Am currently changing resistors in the oscillator/amp section, lots of all the Rs in

the set have gone way high.

The thing is beautifully made, but being tropicalised and having lots of

laced cableforms, it is a nightmare to work on.

It all works, 30W out, but the RX is rather deaf.


A vario would be great to have to make the setup complete, but I may not live long enough to see one.....!


Cheers


Martin G4JSX






Martin Owen 07802 982698, 01788 832324


David_Dunlop
 

Hello Martin and welcome to the site. I am sure you will find it a great combination of useful information, with an acceptable sprinkling of ‘crazy’! 

Not sure if you knew, but there was an Aerial Matching Unit No. C1, also issued for the Wireless Set No. 29. It comes in a case dimensionally identical to the ones for the B-Set and PSU and mounts on its right side with four screws roughly on the top centre of the A-Set. It was designed and built by Canadian Marconi Company for the 29-Set, and to my current knowledge, was the only major component of the set outsourced by RCA Canada to another company. The interior is a work of art and a near clone of the tuning setup CMC had used in their Wireless Set No. 52 Sender. I have an AMU for sale at the moment. Working, and to my knowledge complete internally. I have no circuit diagrams for it but a previous owner swapped out two of the three ceramic aerial posts on the front of it for a pair of UHF sockets. The work looks very reversible if correct ceramic posts were located, and I suspect they were probably a commercially available item back in the 40’s an 50’s. 

Anyway, again, welcome

David
VE4DTD


Jacques_VE2JFE
 

Hello Martin,

 

About the resistors in the CDN #29 set: they were not better than the ones used in the CDN WS #19.

RCA Victor in Montreal used IRC brand parts, made by Renfrew Electric in Toronto.

They were basically made of a layer of carbon deposited on the surface of a glass tube substrate, which was encapsulated in a low density phenolic.

With the time passing, moisture penetrate the phenolic and breaks the bonds in the carbon layer, making the value going high irremediably.

Not only the resistors had to be changed, but all the Paper-In-Oil (PIO) capacitors too.

With the technology used at the time they were made, they cannot be expected to be reliable 75 years later.

All of those developed leakage at various levels and -at least- a tenfold raise of Equivalent Series Resistance (ESR) due to the oxygen absorption of the impregnation oil inside their cases.

Maybe the main cause of the “deafness” of your receiver is due to the circuit decoupling PIO caps degradation.

I will send you a document that partly explain why the #29 variometers are even more rare than the sets themselves, and what was the fate for most of those, at least for the ones that were in Canada by the end of the ‘50s.

Highest serial number known is C 02078, suggesting that no more than 2500 sets were made.

 

73, Jacques, VE2JFE


Martin Owen
 

David


Many thanks for the warm welcome and the AMU information.

I was not aware of the existence of such a thing!

You say you have one for sale,what sort of price are you asking, and do you have

any photos!


Kind Regards


Martin G4JSX





Martin Owen 07802 982698, 01788 832324


David_Dunlop
 

Hi Martin.

I have placed four photos in the Photo Album Section under "Wireless Set No. 29 Aerial Matching Unit".

This little gem arrived on my wireless bench a few weeks ago. Never knew they existed until this one arrived and I was even more intrigued that it was a Canadian Marconi Product built for an entirely otherwise RCA Victor Canada Wireless Set. 

This one was used by somebody who thought removing a ¼-turn fastener and replacing two ceramic aerial terminals with UHF Sockets was a huge improvement. However, internally, it all still appears to be there. I am suspicious the ceramic aerial terminals were off the shelf items from some supplier. A quick browse of photos of them on the internet suggests good, if not identical matches could be found with a little patience.

The four screws on the right side of the case are mounting screws that allow the Matching Unit to be secured on top of the 29-Set A-Set Case. One screw is missing, but underneath it and that horrid aluminum paint is very original wartime Semi-gloss Olive Green paint as used by Canadian Marconi. 

The screw on the back of the case secures a large guide pin that engages a set of holes in the chassis when it is being removed or returned to the case, to prevent damage to the tuning coils, and large phenolic resin mounting plates. Somebody did manage to chip the corner of one plate slightly, however, but no structural significance to the damage.

It is not until you see the tuning coil arrangement inside the Matching Unit that you realize why RCA called CMC in as a sub-contractor for this part of the 29-Set Project they had undertaken. The tuning coil setup is almost a carbon copy of the PA LOADING circuit Marconi used in the Sender of the 52-Set, and it had proved a very successful design. No need for RCA to have wasted time reinventing the wheel. 

Only ever seen photos of one other one in Canada to this point in time.

I am asking $100 Cdn for it. It weights less than a 4 kilo bag of sugar and I would guess an all in shipping weight would be in the 15 pound range.

Hope this info is helpful.

Best regards,

David
VE4DTD


David_Dunlop
 

Just a heads up for everyone that since COVID Regs are once again getting ramped up in these parts, I have decided to withdraw the AMU from sale. The fewer places I have to go to, the better, for the time being.

David
VE4DTD