The PHILCO Phorum

ALL, I have finished the recap on the chassis. My speaker is in the cabinet in the garage so I cannot hook it up at this time. Can I power up and not hook up the speaker just to make sure everything is now OK.. I have a dim bulb tester with a 60 watt bulb. I also have a 200 watt bulb for initial testing when everything is back together.. Can I put in all tubes with the 60 watt bulb or do I have to use the 200 watt.

Remember I do not have the speaker or the turntable hooked up yet..

So what I am really asking is what tests I can do now without the speaker and turntable..

Or do I have to move the chassis out to the Cabinet and hook it all up..[b][/b]


Thanks
Skip...

I would not recommend it. Why would you even want to do that.
the only thing to do without speaker is to.power up without the rectifier tube, so to check the power transformer. Otherwise, no, don't.

Don't do it! You'll run the risk of taking out the rectifier tube, the input filter cap, and or the power trans. Without the speaker connected there is no load on the HV side of the power supply. This will cause the input filter to charge up beyond it's voltage rating. This in turn will cause it to short. Next goes the tube then the trans.
Terry

Well, that is, what Terry said does not necessarily happen but has a chance to happen, and is known to have happened.
Not only that, ven if it does not go up in smoke, there is nothing to discharge e-caps from 500V they have been charged to, and you run the risk of touching that, and it will be one of the loudest ouches that you evere said.

Thanks. You guys have made your point very nicely. I will hook up speaker and then power up .. I assume I don't need to hookup Phone if I don't select it.

To be on safe side I can hook up thru the dim bulb tester with a 200 watt bulb. the radio states its 125 watts . I read Bulb should be 1.5 to 2 times input wattage. Which would allow the radio to work. Please correct me if that is not true..


Thanks again

Skip...

Skip,

1. Have you tested all your tubes.
If not, DO NOT power up unless you know for a fact your radio tubes are at least not shorted, AND your rectifier tube is full good.
Forget dim bulb, it's a dumb thing to do anyway. Not even sure why people use it.
2. Before you populate tubes, without ANY tubes test your transformer. If you do not have a variac, OK, use the hotdammit dim bulb. Make sure the outputs measured at AC are good.
3. Check for the load short across first and second electrolytic cap. (108 and 47A).
4. Now you could power it. Keep your meter on one of the above caps, your hand on the power switch. Your voltage should go up in about 30sec, all the way to almost 500V, and then in a few sec start dropping down to mid 300 or so (rought estimates). If no smoke start escaping, you can start working the radio.

Good advise. Yes all tubes test good. I do not have a variac. If I do more of these I will invest in one.

I did restore a Grunow 654. But didn't have a dim bulb or variac. got lucky nothing was bad.

Alot easier than this one with all the wires falling apart. Used alot of heat shrink on this one.

But looks like I am almost ready to fire it up.

Thanks Again

Skip...

If you have major problem with wire insulation falling apart due to it being guttapercha (rubber) crumbling away due to drying, unless a particular wire is just too difficult to replace due to it coming out of a coil or otherwise not well accessible, usually the advised course of action is full replacement.
I made ampn exception for white (beige?) wire n my radio, it was as flexible as it ever was, different color rubber ages differently, black and red being the worst in AK radios, but otherwise I replaced almost all of it.

Heatshrink is not really an adequate overall solution. Spot fixing is ok now and then, but bad wiring, if at all possible, should be replaced.

Thanks, Looks like I took on a very difficult radio. Hard to get to most of it. I am sure everyone has seen the bottom of these..




Didn't expect such a mess. But for 65 dollars and the cabinet was really good So i took it. Found it in a antique store near Kutztown, PA

Lesson learned. However I will make this work..

Thanks
Skip...

Looks like you got one of the Philco high end sets. Nice when working but no fun to referb.
Terry

Ok Radio powers up OK. Volume is very low can hear a low hum when all the way up. NO signals on any band. even with my signal generator. Almost seems that the push buttons for changing bans are not working. The on off button does work.

Hard to tell. But I think I would get something on some a band. no change in volume when changing bands either. Even with no signals I would think volume should be noise.. But i am not getting that either.

What would be the next step..

Thanks
Skip...

Time to pull out the generator and start signal tracing.
For starters detector tube grid cap touch (careful with it) can give you an idea if the detector tube and all down to audio is working.
But...you will need to trace anyway.

ALL, Since there are no more answers to my questions. I want to thank all who responded. A lot of good suggestions. Was looking for a little more help on troubleshooting. This radio doesn't have grid caps.. The tubes are all loctal except for the rectifier. 7C5, XXFM, 7A4 etc. Anyway thanks to all..

Please close..

Thanks
Skip...

Skip,

It is difficult to just tell you what to do, as you are there and we are not.
I do not know your proficiency level with tubes, so until I (we) do, telling you "go there touch that" would be geopardizing your life.

If though you poke around more and tell us what gpyou see and measure, we will be able to help you a bit more.

When I say grid caps, well, if there are no caps there are still grids, so same technique applies except the. grid is a pin, it is close to other pin and touching it becomes more difficult.

Start with something. If you know what you are doing, touch those grids.
Measure some Voltages. You gotta start from somewhere.


PS. Do you have any equipment? I mean, other than a light bulb.

Ok Thanks. I need to get better documentation and schematics that I can read. I did send for some from Chuck Schwark. Hopefully this has voltage and resistance readings on schematic and a much bigger schematic.

Its hard to read what I have. I just thought that maybe someone would have encountered this problem before and help on what they did.

I do have equipment Signal Generator, Scope, VTVM, Output meter, HP AC voltmeter. ETC..

I guess I was just looking for an easier way out without starting from scratch. Silly me.

PS I was able to get a signal thru by hooking up the sig gen to terminal # 2 on the antenna input , thru a .1uf cap. Signal was weak had to apply approx -20 dbm (to be able to hear the sig..) this was on AM band. So all is not dead.

Thanks
Skip..