Hello,
I have a ESCO console radio and it has 2 canister capacitors with three leads out plus a lead going to the top of adjacent valves.
How can I identify capacitance and how can I replace them so as to keep the existing cans in situ please?
The aluminium is corroded and I can see no marks to identify.
Why is threr a wire from the can to plg into top of the valve?
I have been unable to get any information on this radio or a circuit diagram.

Many Thanks
Gary

Radiomuseum has scant details on the Esco brand other than a few references to British crystal sets of the 1920s.

Top cap connection to valves are usually for the anode or grid, the latter being more common in my (limited) experience of them.

Forgive what may seem an obvious question but are you sure those cans are capacitors, and not inter-stage coupling or IF transformers?

As to the question of dealing with above-chassis multi-section electrolytics, which are usually associated with power supply filtering, you can re-stuff them with modern electros if you can determine the specs of each section and the working voltages.

I am about to do that with a 1959 Hammond organ I'm restoring.

Here's a link to one of numerous Internet articles on the subject:

http://antiqueradio.org/recap.htm.

GTC
You may be right about my not identifying the parts properly.
How can I send or place a picture here to show you?
Also generally with a can style cap how do work out the value?

Cheers
Gary

Re pictures, you can either email them to Brad (see his profile for his address) and he'll host them for you, or place them on a free public photo file server such as Photobucket and then post an image link here.

Re identifying the value of canned electros, the article I linked in my previous post discusses that. Scroll down to the section headed "Multi-section vertical mount".

I haven't yet encountered one of those types of caps without any markings on it, although I guess it can happen.

Also, can you let us know the valve line-up in that set.

Certain chassis-mounted condensers can have two actual condensers inside them and thus three leads, usually two positives and a common return lead. These were most common on the last of the AWA Radiolettes. To replace them it is a matter of using normal axial electrolytics in place, being very careful to get the orientation and values correct. It is correct to disconnect the old condenser, leaving it in place on the chassis for decoration.

The values are written on the side of the condenser however if these have been rubbed off then you will need either a circuit diagram or a capacitance meter (assuming the condenser is still at its original value.

I am new to radios so when I got this one I was given this hand drawn circuit. It gives valve labels but I can only see label on one.

Link to photobucket is:
http://s1085.photobucket.com/albums/j423/vintageradioguy52/.
Thanks for your help.

Gary

I'd never heard of Esco as a brand of radio before so I would say that is a very rare set, probably from around 1932 going by the crescent moon tuning dial.

I am wondering if it is the same as a company called Esco (owned by HPM) that makes electrical fittings for hospitals.

Thanks for the assist. From the above chasis pics do you see any cans electrolytic?

From what I see it is an Autodyne (Screen grid) radio.

There are no caps topside they are IF's and the oscillator & aerial coils. Unless the wire is crook (and its' likely silk) leave it alone and do not dismantle the cans.

Its' s probably around 1932. Tha ARTS&P label should confirm.

The UCC's with red ends are the filters and electrolytic. Replace them with 500V type, no less, depending on the AC volts from The secondary. I doubt they are original.

The set is back biased so they look right with the first one going to the CT.

I have issues with the cathode circuit of the 58 and the wiring of the 57.

The only Autodynes I have had serious dealings with was an EMMCO (Silicon Chip August 2009) and an STC. I would have expected the RFC in the grid circuit..

I will see if I can spot anything similar. It may well be a re-badge.

Marc

I was wrong about the year of manufacture. The ARTS&P shows it as a 1934 model. I thought the crescent tuning dials were out of vogue by then. The chassis looks too well made to be home made. The perforated valve sheilds look quite unique.

Here's what I can find with that valve line-up:

(Brand,model,type,year)

Airmaster,C25?,AC BC Con,1934
Croyden,5V,AC BC Man,1934
Eclipse,Croyden,AC BC Man,1934
Eclipse,Croyden 524,AC BC Con,1935
Eclipse,Univox 524,AC BC Con,1935
Essanay,M447,AC BC Man,1933
Essanay,5MS,AC BC Man,1934
Huckell,Eureka,AC BC Con,1933
Kriesler,4/5 AC,AC BC Con,1933
Palmavox,4/5,AC BC Man,1934
Seyon,25,AC BC Con,1933
Telaverta,425,AC BC Man,1935

Some are mantel (Man) and some are console (Con).

Output end has similarities to STC 57. That was a fairly common run of valves for autodynes. All of the RF section was Pentodes.

The power input plug is the same style as EMMCO

EMMCO was 75-425 and the chassis stamp is in the same style, on this set actually looks like 45-246

EMMCO manufactured several brands of radio and later became EMAIL

Electricity Meter Manufacturing Company

Marc

"on this set actually looks like 45-246"

In photo #12 it looks to me more like 45-346.

That power input plug ought to be a good clue. Did anyone other than EMMCO use it?

Great!! This helps a lot.
In the photo of under the chasis there is a black cap with no label. I removed it and had it tested and it came back as 9 Pfd. This does not seem right for the size of the capacitor. I think it should be higher value. Any thoughts please.

Many thanks for all this help.

Gary

Many of the old wafer type Mica caps were big The actual number of wafers & plates govern the capacity.

Where is it in the circuit?

Highly likely EMMCO made the plug, transformer chassis, etc. They had the facilites.

The tuning gangs on AC5 , DC 5, were their's & they did make radio parts. Some of their chasses were Cadmium plated AC5 was.

Those two big holes in the chassis are where the two "Wet" Electrolytics were"

Marc