Hi everyone. Yet another restoration project underway. Although this has come to a dead stop unless I can get some help.
A customer brought this in a few months ago. It belonged to her grandmother, and the fault is there is no sound.
A more thorough assessment has brought me to the speaker. The specifics of the 11-42 model, (which this is) tells me its a PDyn loudspeaker (moving coil)

The speaker and the coil are separately mounted, this is to say, the coil is mounted on the radio chassis, with wires running to the speaker.
I don't hear anything through the speaker (except valve hum) and it looks very old and worn. It measures approx 27cm across. The paper material is intact, however is brittle.
I have sent in some pics of the unit, in the hopes I may get help in sourcing replacement parts for it.
Thanks for any advice.

The speaker and the coil are separately mounted, this is to say, the coil is mounted on the radio chassis, with wires running to the speaker.

I take it you are referring to the output transformer being mounted on the chassis?

Kriesler output transformers have a reputation for failing.

According to the schematic, it has a 7000 ohm primary and 3 ohm secondary.

It is amazing to many how well the majority of the old sets perform after they have a birthday & get realigned & dragged back into spec. Once you have rid it of leaking caps & bad resistors, the whole thing should perform as good as, or without caps that always leaked, better than it ever did.

Marc

Thanks GTC. That is correct. What I need to know now is where I could source such a transformer. The Speaker is a Jensen 5" according to the schematic, however in reality its more like 10". Any help to source these is appreciated

In the subject line you say radiogram, but you give the model as 11-42, which is a mantel radio with a small speaker. Are you sure about that model number?

Also, if you can hear hum, that tends to indicate that the speaker is working. Mains hum is usually the result of failed filter capacitors in the power supply. A radio of that vintage would definitely be a candidate for "re-capping", that is, replacing the electrolytic and wax/paper capacitors.

To your specific question: the two usual sources for transformers are (1) another radio/someone's junk box (2) purchase new.

New transformers are not cheap, but they are available. Some sources are Evatco in QLD or eBay, for example:

http://www.ebay.com/itm/OT10SE-USA-Single-Ended-Output-Transformer-12VA-5K-7Kohm-4-8-16-60mA-/151641257588

However, I would first check the existing transformer for primary and secondary continuity.

I too am having a bit of trouble with the model number and as to whether it is a mantel or radiogram. I can't find any Kriesler models using 10" speakers.

Along with some pictures can you also include the valve line-up & if it has short-wave or just broadcast (AM) only.

I agree that the output transformer is probably ok going by the hum. If it uses a 6M5 for the output valve, the earlier "Innoval" types were known to be troublesome.

I tend to find two in around eight Kriesler's have a good speaker transformer & the tar coated ones even in HMV nippers have the greatest attrition rate.

Do be careful with speaker transformers tucked away inside the pan. Often they are mounted on insulation. If so it is liable to have B+ on it. If caps have not been changed, resistors checked and the old electrolytics that are likely the cause of hum & often loss of "B" voltage, are changed, then fault finding tends to be a waste of time, better spent doing the previous. The plate bypass cap of the OP valve is one of THE most likely caps to fail in all of the valve sets.

The OP transformer & speaker are easily checked as a unit before the set is even powered. You just get a 9V transistor battery and strike the wires across the primary (set not powered) and the "crackle" should be heard in the speaker: If not then you go look for why?

Marc

Yes GTC It is definitely an 11-42 radio. While I understand that this is indeed a mantle radio, the schematic diagram matches the radio contained in the radiogram unit.
This 11-42 radio must have been chosen to be in the 1954 Duplex Radiogram. See
http://www.radiomuseum.org/r/Kriesler_duplex_5_11_42.html.

To answer everyone, I have replaced all valves, including the 6M5, and all electrolytic capacitors, which leaves the speaker transformer. Thanks for the website looking for transformers, I'll take it from there and see how I go.

I think what you might have is an 11-51. The circuit is indeed the same or very similar to the 11-42.

http://www.kevinchant.com/uploads/7/1/0/8/7108231/11-51.pdf

Agree model 11-51 sounds like the candidate. Schematic says 12 inch Magnavox speaker.

That leaves the speaker transformer, is not a statement that sits well with me. There seems to be a methodology failure.

Before even laying hands on cutters or a soldering iron. The speaker & speaker transformer could have been tested with the battery, as above. Then you would at this point in time definitely know if the speaker, or its transformer, had actually failed, or not.

Unless you check it, you will never know & you may find that it is a completely different issue.

Marc