Philco model 18 (code 121) - HELP! - Printable Version
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RE: Philco model 18 (code 121) - HELP! - Pithicus999 - 05-14-2013
Mondial,
I was trying to see the path on the schematic (going to highlight the low/high voltages) to discover the voltage issue. I’m using Nostalgia Air to locate the inner-tube workings but isn’t working for me. Is there another site that shows the orientation of each pin of a certain tube so that when I look at the schematic I can clearly see the wire connections of each pin in any tube?
Also, I will take your advice, but it may not be until this weekend unfortunately since I don’t have the set at my place.
Thanks.
RE: Philco model 18 (code 121) - HELP! - BrendaAnnD - 05-14-2013
In all the Rider's schematics I've seen, (which is what Nostalgia Air uses), you can count the pins easily on the diagram: Start with the filament pin on the left (looking at the diagram), this is pin 1. Each pin in turn is 2, 3, 4, etc., with grid caps shown separately with a [ on the side of the tube.
If you want really good service literature, Philco Repair Bench http://www.philcorepairbench.com/schematics.htm is the place to go for complete literature. Steve Johnson also has some very nice schematic packets available for download http://www.antiqueradioschematics.org/philco.htm
RE: Philco model 18 (code 121) - HELP! - Mondial - 05-14-2013
Right under the schematic from Rider's is a diagram of the bottom of the chassis with all the tube sockets labeled as to tube element. You may have to magnify the diagram, but the socket pins are marked P, K, Sg etc.
http://www.nostalgiaair.org/PagesByModel/149/M0013149.pdf
RE: Philco model 18 (code 121) - HELP! - Pithicus999 - 06-10-2013
Nastalgia air wasn't working for me before when I looked for the pin diagram, it's working now though. I'm going to retrace the pins through the diagram and find the high/low voltage points. Hopefully I may find a bad resistor or cap.
I just checked the pins on the 80 tube and they are reading 470 volts...a tad high I would say.
RE: Philco model 18 (code 121) - HELP! - jerryhawthorne - 06-11-2013
Pith, it has been so long, can you give us an update on how the radio is now working? Getting stations, where they should be on the dial?
Jerry
RE: Philco model 18 (code 121) - HELP! - morzh - 06-12-2013
Pith
Which pins of 80 and relative to what? Plate-to-plate?
Also, was the radio fully populated and drawing current ?
Also, are you using a DMM or an old 10K/V meter?
Also, are you running from the Mains at 120V or so or are you using Variac and running of 110V? If you are using Mains, remember, 10% of 110V become roughly 40V at 400VAC output which then will turn into 56VDC if unloaded.
RE: Philco model 18 (code 121) - HELP! - Pithicus999 - 06-13-2013
Sorry guys no time this week to work on the radio. But here is the status. The 80 tube pin-pin was over 470. But, given that I moved the radio back and forth to my parents and that it currently is not working I'm planning on checking all voltages again.
Also, I still have not verified that the signal generator is working. The light comes on but there is no 'Hum' or sound of any kind while hooked up.
That being said, while it was hooked up and I made tuning adjustments (prior to this current voltage issue) I was able to see the multimeter rise to the highest voltage point (at each of the tuning stages) AND the actual static or 'sound' coming from the radio itself was increasing...I guess what I'm saying is it seems to me that the sig generator is more of a guide at this point. On the other hand, the set isn't working now so maybe I'm way off.
About the antenna, it wasn't until I repaired the internal coil (I have a pic I should post!) that I was able to get a station. I've since added an external wire (it's thin, same gauge as the coil wire, 30?? I think?) and it's about 3-4 feet long. But it's not a loop or a cross its just a 4 ft wire. Will that antenna work?
I'll do some checking to see where my voltage issue is and then report back.
RE: Philco model 18 (code 121) - HELP! - jerryhawthorne - 06-13-2013
Pith, you are just roaming around aimlessly. Find someone who has a scope/frequency counter and check out your sig gen. If you don't know if that is working properly your lost. I would not worry much about your voltages at this point. You can use your sig gen to figure out if you have other problems. It is a nice piece of test equipment but you need to know if it is working. As stated above, voltage measurements are important but can vary a lot depending on many things. If it is working you won't be tuning to "static", you will be tuning to an annoying tone.
Jerry
RE: Philco model 18 (code 121) - HELP! - Ron Ramirez - 06-13-2013
Pithicus, I have another suggestion: Contact the Michigan Antique Radio Club and join up. They are having their biggest meet of the year in two weeks' time - Extravaganza in Lansing. Perhaps they can put you in touch with someone in your area who may be willing to sit down with you and help you out? Just a thought.
RE: Philco model 18 (code 121) - HELP! - morzh - 06-13-2013
A properly working signal generator is not a guide but an exact standard (for this purpose) allowing a precise enough alignment.
If you do not know your measurement equipment is working properly it is as if you are not even measuring anything. The purpose of alignment is to align and not "kinda sorta" make the static louder.
RE: Philco model 18 (code 121) - HELP! - Pithicus999 - 07-23-2013
I was away for a bit, had a big vacation last month and needed to tie things up at home.
I just took some voltage readings as the radio still doesn't work (I did add an antenna, just wanted to mention that because I don't think I told you yet.)
I think I may know the problem and I'd just like to bounce off you real quick to get your input. First of all, EVERY 'P' to 'K' and 'SG to 'K' voltage reading for ALL of the 42 tubes is ZERO....nothing.
But, the power is going somewhere. The 80 tube reading for 'P' to 'K' is super high, it's 476 and it should be 350. (I'm using the DC measurements).
Looking at the schematic near the 80 tube I see that #51 the ‘Filter Choke’ is connected and I thought it may not be working properly since the power seems to be stopping at the 80 tube. I tried to take a resistance reading across the 2 contact points of the ‘Filter Choke’ and it was way over 1 million…so I thought that was really super high.
I then decided to feel the ‘Filter Choke’ and it wasn’t even warm. So I think I need a new one? Right?
One question, if I DO need a new one where can I get one, AND more importantly what spec do I need? Do I just ask for the one that is 166 Ohms like on the schematic?
Also, my shadow meter light is dead, where can I get one of those and does anyone know what size it is?
Thanks!
RE: Philco model 18 (code 121) - HELP! - morzh - 07-23-2013
Seems like your filter choke is open. The high voltage on the 80 is due the absence of load because of it.
Warm or not, if it shows in megaohms....you know the answer.
You can temporarily try a power resistor, just to make sure the rest is working.
As for the choke, try to find the inductance data on it and the current rating. Of course DC resistance means something also as it drops the voltage. If the choke you find has not enough resistance you can always compensate with adding a power resistor in series.
RE: Philco model 18 (code 121) - HELP! - BrendaAnnD - 07-23-2013
To test whether a new choke will solve your problem, you can use a 250 ohm 10 watt resistor in place of it. If the set comes to life, or at least starts giving voltage where it currently is not, then you can figure on replacing it. You should be able to get a replacement from AES.
There are a couple different lamps used for the shadow meter. If it's the screw in type, you would use a #46. If it's a snap-in type, you can use a #46 or 44.
RE: Philco model 18 (code 121) - HELP! - jerryhawthorne - 07-24-2013
Dang Pith, this thing is going backwards. On prior posts you were getting some sound out of the speaker and now your getting no voltages anywhere? Not having worked on this model but it really sounds if you don't have the speaker plugged in. The speaker with it's field coil allows the B+ voltage to continue to the set. If your meter is set to DC and you get no voltage on the plates of any of the tubes, either the speaker is not plugged in or it's field coil is bad.
After that nice vacation, and all that relaxation, did you forget to do that?
Jerry
RE: Philco model 18 (code 121) - HELP! - morzh - 07-24-2013
Jerry
He said he buzzed it and it is open.
Also this set uses a separate choke first and the field coil then.