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 Post subject: Getting started in the Radio Restoration Hobby
PostPosted: Aug Tue 16, 2022 9:31 pm 
New Member

Joined: Aug Mon 15, 2022 4:36 pm
Posts: 14
Location: Burlington Wisconsin
WHERE DO I START

A couple of weeks ago I was having a discussion with a young man in his early 20s about Antique Radio Restoration.
He wanted to know how he can get started in this hobby and what equipment is needed.
I told him that there are many articles written about the subject on the Internet, just google it.
Well, he pointed out that a lot of the information he found makes the assumption that the
reader already has some knowledge and is equipped with tools and test equipment.

In this post I'm going to attempt to answer some of the questions that beginners may ask.
I'm sure that I haven't answered everything, I'm hoping others will chime in and add
their wisdom and experience to this thread.

SAFETY
Before jumping into restoring Antique Radios you MUST understand that these radios contain
VERY HIGH VOLTAGES. Its not unusual for them to contain over 600 volts.
BE VERY CAREFUL when servicing these old radios, they can KILL you.

BOOKS
The following free PDF documents are excellent for the beginner and experienced.

Elements Of Radio Servicing is very easy to read and learn from.
https://worldradiohistory.com/BOOKSHELF ... y-1947.pdf

The Sylvania Servicing Radio and Television with a Vacuum Tube Voltmeter is another good book to read.
It shows how to troubleshoot radios using a VTVM and goes into a lot of detail.
http://www.cfp-radio.com/documentations ... a-VTVM.pdf

Vintage Tube Data manuals. This site is a gold mine.
http://www.tubebooks.org/

The RCA Receiving Tube manual.
http://www.tubebooks.org/tubedata/rc30.pdf

The Vacuum Tube Shortwave Radio by Richard McWhorter
https://www.pdfdrive.com/the-vacuum-tub ... 69614.html

TEST EQUIPMENT
This Hobby can be very expensive. Test equipment is not cheap even used equipment can be pricey.


ISOLATION TRANSFORMER
The Isolation Transformer is probably one of the most important pieces of test equipment
that you MUST have, it will save you and your test equipment from dangerous voltages.

It contains a 1:1 ratio transformer isolating the incoming house line. Be aware that
some Isolation Transformers are NOT true Isolation Transformers, their ground and neutral
may be connected together, they are known as Medical Isolation Transformers designed to filter
electrical noise. There are a lot of good YouTube videos showing how to verify if your Isolation
Transformer is actually Isolating. A good video to watch is by Uncle Doug on YouTube.

https://www.youtube.com/watch?v=5SjVm-rF39A

The type of Isolation Transformer to get is the Technician Isolation Transformer. If you
can't find a Technician type then the Medical type can be modified to be a Technician type,
view Uncle Doug's video.

I use a Sencore PR-97. This instrument has a Technician Isolation Transformer and a Variac.
Always remember, a Variac IS NOT and Isolation Transformer.

DIM BULB TESTER
This tester has been around forever and can be constructed in no time. It took me a little
over an hour to build mine. Google it and you'll find many simple designs. The Dim Bulb
Tester simply places a 120 volt incandescent light bulb in series with the radio's power cord.
If the radio under test has a power supply problem, a short circuit or bad filter capacitor
the Dim Bulb Tester will glow bright consuming the electrical current instead of the radio
throwing sparks, starting a fire and blowing the house breaker. I was working on a
Hallicrafters S-38C radio and I had it plugged into my Dim Bulb Tester. The radio was working
just fine and was playing in the background then all of sudden the "Death Capacitor" shorted.
Oops I forgot to replace it. The house didn't catch fire because the Dim Bulb Tester did it's thing,
consumed the current.

DMM (Digital Multi Meter)
Modern DMM are very accurate instruments used to measure Resistance, Voltage and Amperage.
Some will also measure Capacitance and Diodes. There are many brands to choose from
and not all are accurate and reliable. Don't go cheap when selecting a DMM. I once had a
Harbor Freight DMM that sold for about $15, it was so inaccurate on all scales that it wasn't
usable. My main DMM now is a Brymen BM867s, $170.

VTVM (Vacuum Tube Voltmeter)
A VTVM is used to measure Resistance and Voltage. The difference between a VTVM and a DMM is
that the VTVM uses a meter to display the readings. My vintage RCA WV. 77E is somewhat
accurate but I'm not looking for accuracy with the VTVM. When I need accuracy, I use my DMM.
When I align a radio I connect the VTVM to the radio's AVC (Automatic Volume Control) line
and set the VTVM to the -DC setting. Its much easier to watch an analog meter than a bunch
of changing numbers on a DMM. There are tons of VTVMs on eBay, Heathkit, RCA, Sylvania, HP.
You don't need to get the best, Heathkit is a good choice.

SIGNAL TRACER
Sometimes you'll be working on a radio that lights up and no flying sparks. You hear
a little static coming from the speaker but no stations are received. A Signal Tracer
is used to find within the circuit where the signal is stopped. I use an old Eico 147A
Tracer. It helps considerably in finding the lost signal. You can find these on eBay.
Heathkit also made good Tracers.

SIGNAL INJECTOR
A Signal Injector is a small hand held battery operated instrument used to inject a
tone into the radio circuit. I use it to troubleshoot the radio's audio stage. It also
doubles as a small noise transmitter. By moving it around and above the circuit, it
transmits a noise into the radio allowing you to trace where in the receiving circuit
where the signal gets lost.

OSCILLOSCOPE
In most cases the oscilloscope is not really needed. It can be used to trace signals,
measure voltages and look at the quality of the signal. I do use an oscilloscope
when working on the radio audio section or audio amplifiers looking for distortion and
clipping. If you must have an oscilloscope then buy a new one like Rigol or Siglent.
Used oscilloscopes on eBay are pretty used up or on their last leg.

TUBE TESTER
A Tube Tester is a must for obvious reasons. There are many on eBay, look for Heathkit,
B&K, Hickock. Just make sure it tests the majority of tubes you intend to use. Typically
the more modern (1970s) testers will not test the older 4 pin tubes and some of the
older testers will not test the 7 and 9 pin tubes.

RF GENERATOR
When you get the radio working you will need to align the IF, RF, Antenna trimmers
and PADS. This is performed using an RF Generator and many can be found cheap on
eBay. When performing the alignment on a gem like a Hammarlund or a Collins then
it becomes frustrating using a vintage RF Generator that drifts and has an
inaccurate scale. I started with an old Eico generator and it was very
frustrating to use. Modern RF Generators not only produce very stable RF signals
but also double up as Frequency Counters. Modern generators have the ability to
sweep a frequency range and also have trigger outputs that connect to an Oscilloscope
so you can view the frequency response of a circuit. The generator MUST also be able
to generate a modulated signal for both AM and FM. Buy the best modern generator that
you can afford, you won't regret it. I use a 160 MHz Siglent SDG5162.

TOOLS
You will need a ton of specialized tools that you may not
find at your local Hardware Store. Over the years I've
accumulated so many tools for this hobby, most I use
often and others on occasion.

SCREW DRIVERS
I have amassed a large collection of screw drivers, every one different and all of high quality.
High quality is a MUST. There is nothing worse then stripping the head of an unobtainable screw.
I have long ones, short ones and regular length drivers in both flat and Philips. You will also
need a set of plastic Radio/TV alignment screw drivers. Check eBay for these.
My favorite small screw drivers are the Wiha 26199 set and the Wiha 26192 long screw driver set.
Both sets can be found on Amazon.

NUT DRIVERS
Nut drivers are a MUST. Get a set in the 3/16 to 9/16 range and make sure they are hollow shaft.
Xcelite makes a set that are solid shaft, not very useful when removing a nut from a panel switch.
A specialized Nut Driver that I use a lot is used by Luthiers. It is used to grip knurled nuts that
are sometimes used on panel switches and headphone jacks. It can be found on Amazon -->
https://www.amazon.com/StewMac-Adjustab ... B01HYB9TEU

SOLDERING
When working on point-to-point wired radios its worth buying a good soldering pencil that has temperature
control built into it. I use the Weller WES51 soldering station. Sometimes I use my big 260 watt soldering
gun to solder loose connections to the chassis. Buy a 1 pound spool of 60/40 1.0mm lead solder. Don't buy
that lead free solder. Sometimes you will run across a stubborn part that will not solder. For those cases
I apply a drop or 2 of MG Chemicals Rosin Flux #835-1L

https://www.amazon.com/MG-Chemicals-Liq ... 644&sr=8-1

This flux also makes it possible to solder onto the chassis if need be.
I apply the liquid flux using a small needle bottle.
I also use these bottles to apply oil, acetone (for flux removal) and alcohol.

https://www.amazon.com/Bantoye-Applicat ... 114&sr=8-1

You will also need a Solder Sucker.
https://www.amazon.com/Desoldering-Vacu ... 20&sr=8-29

CHEMICALS
Tarn-X - Used to clean switch contacts, wafer switches... Look for it on Amazon.
DeoxIT-D5 - Used to clean volume controls and switches... Look for it on Amazon.
DeoxIT L260CP - Conducting Grease. Used to lubricate the rotor bearings on a variable capacitor and
maintains conductance to the frame.

MG Chemicals Rosin Flux #835-1L - See SOLDERING above.

Zoom Spout Oil - Sewing Machine Oil. To oil whatever squeaks and doesn't turn when it should. Look for it on Amazon

Freeze Spray - Sometimes a component works well only if its cold. When it warms up the radio acts up.
https://www.amazon.com/Tech-Spray-1672- ... 122&sr=8-3

Compressed Gas - Often you will need to blow off dust from switches, variable capacitors... and you don't have an air compressor.
https://www.amazon.com/Falcon-Compresse ... 22&sr=8-16

Debrox - Alright this one is weird but it works. Debrox is used to remove Ear Wax :D. A lot of IF transformers use Powdered Iron tuning slugs.
Sometimes these slugs become seized in the coil form. Instead of taking the risk of cracking the slug, put a few drops of Debrox in the coil form
and let it do its thing. After 30 minutes or so, try moving the slug. It will eventually free itself and the Debrox will not effect the coil characteristics.
You can buy Debrox at any Walgreens or CVS.

Best Regards
Denis - KB9CHF


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Tue 16, 2022 10:40 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 12:55 am
Posts: 21367
Location: Bryansford Village. Ireland.
Chemical dips including Tarn-X are some of the most destructive tarnish removers. They not only remove tarnish, they continue to etch the object itself! The companies producing these industrial chemicals are deceptive.
â–˛ https://www.hermansilver.com/tarn-x.htm

------------

Metal contacts oxidize with the passage of time
and (shaft) lubrication dries out.

Contact Cleaner is for removing oxides on conductive (metal on metal) surfaces.
Cleaning carbon pots→ viewtopic.php?p=3192382#p3192382

Some Contact Cleaners can and will melt plastic...
read the data sheet kids, and don't lick your fingers... :)


Greg.


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Tue 16, 2022 11:51 pm 
Member
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 41250
Location: SoCal, 91387
I'm afraid the OP might scare some beginners away with it's extensive list of tools and equipment.

All that's really needed to begin with would be a DMM, soldering iron & solder, needle nose pliers, wire strippers and maybe diagonal cutters. The next step might include an RF generator, non conductive alignment tools, and a signal tracer. You just gradually build up your bench as you progress. And one can never have enough .047 capacitors on hand.

Elements of Radio Servicing, BTW, can be found right on this board, by clicking "archives" at the top of any page.

_________________
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins/////////////////////////


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Wed 17, 2022 12:29 am 
Member
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Joined: Jan Tue 31, 2012 12:55 am
Posts: 21367
Location: Bryansford Village. Ireland.
For many years all I had was a multimeter, soldering iron and pencil & paper.
All radios were aligned with the fluorescent tube on the shack's ceiling!

I was 20 years in before I purchased one of those fancy visual multimeter things, called an oscilloscope. lol


:) Greg.


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Wed 17, 2022 1:18 am 
Member

Joined: Jan Thu 01, 1970 12:00 am
Posts: 6765
Location: Minneapolis, Minnesota
Yep that is too many items to start and too many "musts". That list is better suited to an experienced (not necessarily expert) radio troubleshooter. fifties and egg are far closer to the practical truth. Get started just doing it on a lesser / limited basis before going on an equipment and knowledge scavenge hunt. It *is* mighty helpful to learn to trace circuitry as soon as possible as well as understanding some electrolytic cap polarity diagnosing but you don't much radio stage knowledge to start.


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Wed 17, 2022 1:44 am 
Member
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 18297
Location: S. Dartmouth MA USA
Dale Saukerson wrote:
Yep that is too many items to start and too many "musts". That list is better suited to an experienced (not necessarily expert) radio troubleshooter. fifties and egg are far closer to the practical truth. Get started just doing it on a lesser / limited basis before going on an equipment and knowledge scavenge hunt. It *is* mighty helpful to learn to trace circuitry as soon as possible as well as understanding some electrolytic cap polarity diagnosing but you don't much radio stage knowledge to start.
Agreed, as well as considerable use of not only electronic but also colloquial jargon about antique radio. That, may sound picayune but to a noob "Variac", "Signal Tracer", "Oscilloscope, etc. can be very foreign terms. "I" use, this a and that a". Honestly most restorers don't use or even need more than 1/2 of that list and of the remaining very very seldom in everyday repairs. Scary, scary list that can take the fun away and ruin the satiation of repairing a radio or any other broken electronic.

What is not on that list, comes free of charge, everybody has one, (be nice), the brain. The ability to make logical diagnosis based on facts discovered during the "triage" (first few moments of examining a defunct electrical device). There have been many many electronic service handbooks, some very specialized others are generic and the published date will often be useful to know that the book will cover servicing up to that time. But there are also handbooks for servicing the "Antique Radio" One such handbook is on this web site for free as a PDF download.
https://www.antiqueradios.com/archive.shtml

Chas

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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Thu 18, 2022 1:45 am 
Member

Joined: Jun Sat 09, 2007 7:14 am
Posts: 5806
Location: Melbourne, Florida
drrenaud wrote:
WHERE DO I START ........BE VERY CAREFUL when servicing these old radios, they can KILL you. ......
Denis - KB9CHF


As can a bee sting for a very unlucky few. I've never heard of anyone even being injured, much less killed by a radio. The most likely injury is hitting something when you react to a shock.

Isolation transformers are fine but only if you really understand why you might need one.

I went for years with only a VTVM. The most important piece of test equipment is the one between your ears.

RRM


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Thu 18, 2022 3:54 am 
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Joined: Mar Sun 11, 2007 5:55 am
Posts: 13004
Location: Mission Viejo, southern California
Location: Mission Viejo, California
Yes, too many musts. I've never had a signal tracer or dim bulb set-up. I started with a soldering iron an uncle had given me in 1970, an inexpensive multi-meter, and simple hand tools. A tube tester was one of the first things I realized I needed. The first radio I restored had a bad power transformer and every tube was bad! Next, I realized that a signal generator, VTVM, and frequency counter would be very handy. There are some super nice plans on this web site for building a new frequency generator and display.

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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Fri 19, 2022 9:45 pm 
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Joined: Dec Tue 23, 2014 5:51 pm
Posts: 2842
Location: N. Palm Bch, Fl.
If you have very deep pockets then buy everything you mentioned and you'll be ready. If not, then get the tools mentioned above and buy what you need as you go. I do recommend quality hand tools. They make work a lot easier. I got most of my test equipment from members here. Used and I knew they would work right out of the box. Not a lot of whistles and bells, but do everything I need and that's easier on my pee brain.

Freeman

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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Mon 22, 2022 1:20 am 
Member

Joined: Jun Sat 09, 2007 7:14 am
Posts: 5806
Location: Melbourne, Florida
Freeman wrote:
....... on my pee brain. Freeman


Spell check fail.

RRM


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Mon 22, 2022 3:23 am 
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 41250
Location: SoCal, 91387
Retired Radio Man wrote:
Freeman wrote:
....... on my pee brain. Freeman


Spell check fail.

RRM

Now you don't know that; maybe he's referring to the "little head"... :wink:

_________________
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins/////////////////////////


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Wed 24, 2022 4:43 pm 
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Joined: Aug Wed 25, 2010 2:23 pm
Posts: 1673
Location: Tacoma, WA 98407
I first got into this hobby over 30 yrs ago and still don't have half of what's on this list, especially all the chemicals. I've found that the place to find cheap test equipment is swap meets. Granted, it's not like 30 years ago when you could buy a tube tester for as little as $20 (and easily repaired tube radios also for as little as $20) but a lot of other stuff still sells at bargain prices. For example, I bought a decent Heathkit VTVM at a recent swap meet for $15. It will probably cost me another $5 to recap it, but I still consider it dirt cheap.

The best bargain of all is membership in a local antique radio club. The value in that is vastly greater than the $20 or so annual cost of membership.

Tom


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 Post subject: Re: Getting started in the Radio Restoration Hobby
PostPosted: Aug Wed 24, 2022 9:20 pm 
Member

Joined: Jun Sun 15, 2014 4:37 pm
Posts: 2230
Location: Montreal, Quebec
I once found an RCA Voltohmyst, the later model, on the sidewalk. I've not done anything with it, because I had one already, plus the HP410B and musc DMMs.


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