Yep, mains wiring as photographed is not as previously described in original post. As the saying goes: a picture is worth ...

The significance of photo's (as well as a schematic) cannot be underestimated.

It always pays to have good sharp photo's before you attack as this provides a reference, not only to a customer, or showing us where a problem is, but for Senior moments and interuptions, where the question is "where was that" as you forgot to mark it, or a pest invaded.


Marc

Does anyone know anything about how to wire up the mains plug on this set (going by the photos)? I have looked at the circuit diagrams sent to me, but to no avail. All the diagram shows is the mains voltage, it doesn't show which lead is active and which lead is neutral.

Thanks,

Chris

EDIT: I will re-check the transformer and chassis in the morning to see if I can determine anything (going by the advice posted on the first page). In the meantime though, all advice is welcome!

One of the photos that you posted clearly shows the mains wire going in and out of the switch and the other one continuing on.

I am finding it hard to believe that you cannot trace where the piece of mains wire that is not connected to the switch terminates.

Consider the wire on the switch to be active. As I have previously pointed out . The wire from the switch to the transformer, should not need touching.

There is significant disadvantage & possible danger if you cannot interpret a wiring diagram. Reading what is on the circuit is one thing; Interpreting is more of an understanding.

It is critical that you find that mains wire before proceeding. A sharp photo posted (here) of the inside of the Pan showing the switch & transformer area might be useful, in helping us find it?

Marc

Hi Chris,

All the information in on the first page, plug wiring in a post from GTC, identifying the active and neutral wires in a PS on one of my posts and Marcc's post.

Marcc is very experienced and offers very good advice. You're going to be working with extremely dangerous voltages. If you're not 100% sure that you understand what you're doing, it might be best to seek someone out in your local area to give you some help. The Historical Radio Society of Australia (HRSA) has an active NSW North Coast branch so there may well be members in you area.

Brad might be able to identify any forum members in your area as well.

Cheers,

Warren

Hi all,

Thanks everyone for your help! Sorry about my mix-up with the mains lead, but I somehow managed to skip several posts on the first page (don't restore radios on the same week that you have half-yearly senior exams!).

Anyways, all is sorted with the radio, the valves appear to be working, and the speaker also appears to be working. The dial lamps need replacement, so any clue where I can get them (would any stores, such as Jaycar, Bunnings Warehouse, Woolworths etc. carry small 6.4v globes like these?).

I've noticed that even with the power switch (DPST) switched off, there is still power applied to the set (the valve filaments still glow and the power transformer still hums away). Is this a fault with the transformer, or is it just some kind of 'fast start' stand-by feature?

Also, I'm at a loss with the pickup on the back. As shown in the photos on ImageShack, there are only two connections - one pickup and one earth connection. From what I've read, I gather that there should be two pickup connections?

Thanks again for everyone's help!

Chris

I've noticed that even with the power switch (DPST) switched off, there is still power applied to the set (the valve filaments still glow and the power transformer still hums away). Is this a fault with the transformer, or is it just some kind of 'fast start' stand-by feature?

*** DANGER ***

What you have described is a dangerous situation.

No, there is no fast start. When the power switch is off there should be no power to the radio.

In this photo:

http://imageshack.us/photo/my-images/15/img8707c.jpg/.

... that is not a DPST switch. It is SPST and switches just one side of the mains. Whether the side that is actually switched is active or neutral depends on how the plug is wired.

Even though the set will work whichever way the plug is wired, for safety's sake it is the active that must be switched.

If the valve heaters are still glowing when the pot is turned to the off position, then there is still power being applied to the transformer so it seems that either the switch is faulty or there is a wiring error.

You are dealing with lethal voltage here and I am concerned for your own safety.

Please don't attempt any more repairs on this set without the assistance of an experienced technician at hand.

Chris.
It looks like your Kriesler is missing the metal link that is supposed to be inserted between 2 of the connectons, one of them marked "PU" for the radio to work. The 3rd connection is earthed (this can be confirmed with a multi-meter

The link connects the RF stages to the amplifier. When the link is removed you by-pass the RF stages and you can connect a external source to the "PU" terminal which is the input of the amplifier. The external source was originally intended to be a record player pick-up. Nowadays up-to-date sources such as CD players, or even Ipods (mono, of course) can be used. The shielded side of input lead goes to the earth connection.

In some radios these links are attached to a piece of cord tied to the chassis so they don,t get lost when taken out. Maybe yours is hidden away somewhere.

P.S.
In response to GTC's previous post:
Please take heed of his and others advise regarding electrical safety. A lot of us, myself included, know what it is like to get a nasty bite from playing around with old electrical equipment and have lived to tell the tale.

Steve Savell at Radio Revivals;

http://www.radiorevivalparts.com/ .

He has the correct 6.3v globes. I don't know of anywhere else that sells them...

Incorrect globes will draw too much current and/or get too hot.

Thank you both for your advice and concern. I'll try getting in touch with the ORARC, and see if anyone can help.

Will the radio be safe to use as-is (provided it's unplugged when I'm not using it)? The only repairs it really needs are two new dial lamp bulbs, but that isn't urgent. It has a solid case, so there is no chance of getting zapped while it's got the back on.

In the meantime, can I use an RCA audio cable to connect something up?

Chris

I have seen wax paper caps in this set and am concenrned about the mains wiring.

Until such time as that set has been overhauled and the mains checked by someone more experienced that can guide you through the set, I would not turn it on.

Even that I have been repairing radio's for over 40 years. I will not turn a set on just to see if it goes without inspecting it.

I have had one lately that was taken out of service with a "crackle". It still had its original cable & plug from 1948 and I am still amazed that it had not killed some one.

I have an 11-7 on the bench,. that was not turned on & I discovered several faults & an open speaker. That is now being sorted out before I even bother powering it.
A Radiolette clone was found to have defects and wrong components when inspected.

Be wary: Caveat Actor applies if you power unknown sets

Someone mentioned Steve. He will have caps for it.

Marc

I think the first thing to be sure of here is making sure that, particularly in the case of a DPST switch, is that the four wires are correctly oriented. Going a 'quarter turn' with polarity would have you bridging out the mains supply when turning the switch to the ON position.

As it stands, it has been identified that the switch is SPST. In this case, getting things right is a little easier but it is still very important not to fly blind. I will second the recommendation that some in-field assistance be obtained with wiring up this set. It will be an invaluable experience.

The next step is to go about some improvements to your 'workshop'. As I have no idea of what it may look like or how well-equipped it is, the following are merely suggestions and you may have some in place already.

1. Clean bright work area - not the kitchen table, etc.
2. Rubber mat on the floor - about $30 at Bunnings.
3. Work surface made of a non-metallic material.
4. Wear shoes (leather uppers are best, not thongs) and stand where possible rather than sitting.
5. Make sure the work surface is at a good height for standing.
6. If you must sit then the stool should have timber or plastic legs.
7. Power outlets to be protected by an RCD. If your house hasn't been wired to include one, portable ones are available - get Clipsal, they are the best brand.
8. Never, ever, ever, ever work live. There's never a sufficient excuse for it apart from testing a circuit for a working voltage. The dangers with electricity are invisible but definitely there, waiting for idle fingers.

This advice applies to working on any electrical apparatus, not just valve radios.

I'd add to Brad's list:

Never work when you are tired or distracted. Loss of concentration can lead to big errors being made. If somebody starts talking to you, down tools and don't pick them up again until the conversion is finished.

Chris
please heed everyones advice. I am concerned that you dont have the experience or knowledge of the dangers of mains power.

What test equipment do you have? At the very least you will need a mains rated multimeter, fluke is best, but Jaycar do sell some nice alternatives. I would budget for $100+

A megger or insulation tester is handy to check mains transformers.

If you end up with more radios, then it might be prudent to find a valve tester and signal generator.

I would not even consider powering up an unknown radio. I cringe when I read on ebay 'I plugged it in and it hums, just needs an aerial'

My process for repairing/restoring a radio is

Check mains transformer for insulation and open windings
If that is OK, check the speaker transformer/speaker and if easy to get at IF coils.

Re-cap it. Compare what you find with what the circuit shows, being aware that a lot of manufacturers, Kriesler especially usually had eleventy running changes, not always documented. Check resistors, particularly the higher values

Pull the valves, noting what went where.

Replace mains cord and plug, secure cord, fit a fuse, earth to correct standard and make sure power switch (if fitted) wired into Active line

I power up with a variac and check HT and heater voltages.

Remove power, fit valves, and see what happens.

There are a lot more finer details in the process, but generally that should at least decide if its repairable in the first place, and that it is safe.

I realise that your budget is limited, but please play it safe, so you are around for a long time.

If you can identify capacitor values, I am more than happy to shoot you over some,

But please get someone to look over your shoulder.

And I would use a finer grade of sandpaper on the cabinet.

Ben

Just had a better look at your photos. I'm a bit concerned about the insulation on the mains transformer

The blue electro cap in the middle of the chassis looks to have smoke damage, check the resistor nearby.

The grommet around the mains cable needs to be chucked.

I'll grab a pic of my 11-81A showing the PU link tomorrow

ben