I really want to understand old radios.
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I've studied up on basic electronics and understand resistance, capacitance, resonance, etc., went through an RCA radio course on disc, so I get the basics. But, I would really like to know, for example, why a certain resistor is where it is and why. I would like to look at a schematic and understand what all the components do and how everything ties together. I have a couple of cheap old tube radios that I could experiment on. I've also home-brewed some crystal and one-tube broadcast and SW band radios. I may not be expressing this very well, but I hope you get my drift.
Also, I've heard from several people who say resistors or only about a nickle apiece. Where do you find resistors for $0.05? JustRadios and TubesAndMore are around $0.45 each. Do you buy them by the boxcar load? ![Icon_biggrin Icon_biggrin](https://philcoradio.com/phorum/images/smilies/icon_biggrin.gif)
I would be happy to hear from anybody on this subject.
Thanks,
lyle
I may not be very good, but I'm slow.
(This post was last modified: 03-03-2012, 05:34 PM by lyle.)
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Hi Lyle,
Good you have already made strides to understand the basics. To advance further you will likely need to start doing some math exercises on things such as RC time constants, some basic trig for better understanding resonance, phasing, and power factors. Thevenin theorem is very useful for simplifying more complex circuits. Not sure what text books cover all these topics nowadays. But shouldn't be hard to search them out. My 2 cents.
Richard
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Thanks, Richard.
Got the math, but never heard of the Thevenin Theorem. Will take a look.
lyle
I may not be very good, but I'm slow.
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(03-03-2012, 05:31 PM)lyle Wrote: Thanks, Richard.
Got the math, but never heard of the Thevenin Theorem. Will take a look.
lyle
I sucked at math, that's why I never beame an electrical engineer or scientist as my dad wanted. Seems like just about everything can be reduced to an equation or Theorum, except for the unknowns which are conveniently left out of many systems of analysis.
More sh*t than a Xmas Turkey about this available.
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(03-04-2012, 01:23 AM)codefox1 Wrote: (03-03-2012, 05:31 PM)lyle Wrote: Thanks, Richard.
Got the math, but never heard of the Thevenin Theorem. Will take a look.
lyle
I sucked at math, that's why I never beame an electrical engineer or scientist as my dad wanted. Seems like just about everything can be reduced to an equation or Theorum, except for the unknowns which are conveniently left out of many systems of analysis.
More sh*t than a Xmas Turkey about this available.
Me too. I spent a lot of time in math 'stupid study' myself, and my dad wanted me to be an engineer too. No disrespect to them that did, but by the time I would have graduated a lot of them were pumping gas because the demand dropped.
lyle
I may not be very good, but I'm slow.
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Hello, Lyle: You don't have to be a rocket scientest to work on old radios, but it helps. I have been collecting since the '60s, and although I did take calculus and calculus-based physics courses, much of my life (25 years) was spent in the Marine Infantry. You don't learn a lot of electronics there.
So I am pretty much self taught. My advice is to read and listen. Get a good handle on what you know and don't know. This will change as your knowledge grows. Seek out the real experts, listen to them, and be worthy of their company. One of my mentors is an expert named Bob Timms, the knowledge I have gained from him has been tremendous.
Look at the articles here and in the Philco Repair Bench site. Ron's resto projects will give you some lofty goals to shoot for, as he does some amazing chassis work.
Look at many sites for parts. Personally, I use justradios.com for my resistor and capacitor needs, but there are many sources out there. Prices will vary in accordance with the voltage rating, power rating, etc......
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(03-05-2012, 02:41 PM)TA Forbes Wrote: Hello, Lyle: You don't have to be a rocket scientest to work on old radios, but it helps. I have been collecting since the '60s, and although I did take calculus and calculus-based physics courses, much of my life (25 years) was spent in the Marine Infantry. You don't learn a lot of electronics there.
So I am pretty much self taught. My advice is to read and listen. Get a good handle on what you know and don't know. This will change as your knowledge grows. Seek out the real experts, listen to them, and be worthy of their company. One of my mentors is an expert named Bob Timms, the knowledge I have gained from him has been tremendous.
Look at the articles here and in the Philco Repair Bench site. Ron's resto projects will give you some lofty goals to shoot for, as he does some amazing chassis work.
Look at many sites for parts. Personally, I use justradios.com for my resistor and capacitor needs, but there are many sources out there. Prices will vary in accordance with the voltage rating, power rating, etc......
Thanks, TA,
Good, solid advice. You mean the Marines didn't teach you to field strip a radio? LOL
Appreciate your advice and especially your service. Thank you. I'm ex-Navy-Vietnam. A long time ago.
Thanks, again
lyle
I may not be very good, but I'm slow.
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Hello, Lyle:
And thank you for your service! Most of the time I was based out of PhuBai, but also operated out west vic Kontum, Pleiku, and DakTo. Too many little men wearing tan uniforms trying to shoot me. I still dream about it every night.
HA, no, I was told by a radio tech that his worst nightmare was a grunt with a screwdriver. We got pretty good at understanding wave propagation, especially with respect to shortwave radios. For us the radio was a bigger asset than any weapons that we carried, so we made sure to care for them properly.
Do you have a project radio that you are going to work on?
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(03-06-2012, 01:30 PM)TA Forbes Wrote: Hello, Lyle:
And thank you for your service! Most of the time I was based out of PhuBai, but also operated out west vic Kontum, Pleiku, and DakTo. Too many little men wearing tan uniforms trying to shoot me. I still dream about it every night. ![Icon_evil Icon_evil](https://philcoradio.com/phorum/images/smilies/icon_evil.gif)
HA, no, I was told by a radio tech that his worst nightmare was a grunt with a screwdriver. We got pretty good at understanding wave propagation, especially with respect to shortwave radios. For us the radio was a bigger asset than any weapons that we carried, so we made sure to care for them properly.
Do you have a project radio that you are going to work on?
Yes TA,
Working on a Philco 60 for the family Doc. Sure don't want to get it wrong! You?
Spent most of my time on the Ranger (Aircraft Carrier) going in circles on Yankee Station between the mainland and Hainan Island. Not very exciting, except the several times we caught fire with thousands of pounds of ordinance stacked on deck.
Welcome home, TA.
lyle
I may not be very good, but I'm slow.
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Hello, Lyle: well, yes, I am trying to bring an early model Philco 90 back to life but unfortunately at some point in time someone had worked on it and bungled it up! Additionally, I just have discovered that half of the two-ganged volume pot is bad, as it measures 25000 ohms and is supposed to be 250 ohms. I have re-stuffed all of the bakelite, metal, and mershon caps and replaced some WAY out of tolerance resistors. Also think it is wired properly now. BUT must search for a volume control.
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Well, good luck finding a volume control. I have no idea how hard it would be to find one.
Just took the one from the 60 partway apart, so I could squirt some cleaner in. About to tackle the band switch, which was frozen, have recapped and cleaned out the tone control. Should keep me busy until my parts arrive from JustRadios. Still need re-stuff the Bakelite blocks, filter capacitor block, and replace about half the resistors. Evidently the radio played, but was weak. Luckily the antenna xfmr and feed back coil of the osc ohm out OK.
Hey, it says up there under your name you are an expert. Can I put you on my list of people to bother if I get stuck?
lyle
I may not be very good, but I'm slow.
Posts: 2,353
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Joined: May 2010
City: Clayton, NC
Hello, Lyle: I would be glad to offer any assistance that I can, but I must tell you that there are MANY fellows here on the Phorum that are WAY better radio guys than me. What I especially like about this site is the people that contribute to it. Here you have a valuable resource for radio questions.
I'm definitely NOT an expert on wimmen, as two divorces and numerous failed relationships will attest. In fact, I don't even call my ex-wives by their name any more, I just call 'em both "plaintiff."
So wimmen questions are best left for others.
I discovered that the volume control I need was used in several Philco sets, including the 20, 46, and 70. I also discovered that the 1st IF transformer was open, so now I am searching for one of these too....
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(03-09-2012, 11:55 PM)TA Forbes Wrote: Hello, Lyle: I would be glad to offer any assistance that I can, but I must tell you that there are MANY fellows here on the Phorum that are WAY better radio guys than me. What I especially like about this site is the people that contribute to it. Here you have a valuable resource for radio questions.
I'm definitely NOT an expert on wimmen, as two divorces and numerous failed relationships will attest. In fact, I don't even call my ex-wives by their name any more, I just call 'em both "plaintiff."
So wimmen questions are best left for others.
I discovered that the volume control I need was used in several Philco sets, including the 20, 46, and 70. I also discovered that the 1st IF transformer was open, so now I am searching for one of these too.... Hey Tom
I can probably help you out with the volume control from a mdl 20.
Terry
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(03-10-2012, 07:44 AM)7estatdef Wrote: (03-09-2012, 11:55 PM)TA Forbes Wrote: Hello, Lyle: I would be glad to offer any assistance that I can, but I must tell you that there are MANY fellows here on the Phorum that are WAY better radio guys than me. What I especially like about this site is the people that contribute to it. Here you have a valuable resource for radio questions.
I'm definitely NOT an expert on wimmen, as two divorces and numerous failed relationships will attest. In fact, I don't even call my ex-wives by their name any more, I just call 'em both "plaintiff."
So wimmen questions are best left for others.
I discovered that the volume control I need was used in several Philco sets, including the 20, 46, and 70. I also discovered that the 1st IF transformer was open, so now I am searching for one of these too.... Hey Tom
I can probably help you out with the volume control from a mdl 20.
Terry No worries, TA, I don't know enough to ask hard questions. I made a discovery of my own. This Philco 60 has a break in the phenolic wafer of the Band Selector. It is now in two pieces on my bench. It's been suggested I use super glue. Finding a replacement probably won't be easy.
If I can't fix it maybe I can just by-pass it to the AM band. I don't think there really is a police band left.
lyle
I may not be very good, but I'm slow.
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Old Police band is useless. Get rest of set to work.
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