Radio Repair

My Repair Background:

Mark Miner

I'm Mark Miner, Proprietor of Mark's Antique Radio Kollection and known throughout the world as 'The Florida Radio Doctor.'

One of my Zenith Stratosphere 1000Z chassis projects

One of my Zenith Stratosphere 1000Z chassis projects

RCA 'Magic Brain' chassis from 1935

RCA 'Magic Brain' chassis from 1935

The classic mark of RCA--'His Master's Voice'

The classic mark of RCA--'His Master's Voice'

For radio chassis repairs:

  • I begin by removing the tubes and clean the chassis. I then check all basic main components such as power transformer, speaker field where necessary, the output transformer, IF transformers and so forth. I then do preliminary troubleshooting to determine what is needed to bring it back to life.
  • Repairs may include, but not be limited to, replacement of all paper tubular capacitors (caps) and filter caps.
  • Replacement of all caps is more effective than simply replacing the high voltage coupling and bypass caps. I've found through long experience that even low voltage cathode bypass caps that are defective can cause distortion, lack of sensitivity and other unwanted problems. Some repair people make the mistake of leaving the low voltage caps in while assuming they are ok. This is only inviting problems that could degregate performance of the set.
  • I replace any resistors that are out of tolerance, typically replace the power cord with the proper kind and replace any deteriorated wiring.
  • Defective tubes will be tested and replaced as needed.

Once the electrical repairs are complete, I do whatever is needed to replace rubber bushings, spray clean switches and controls, tuner, etc. Then lubricate where necessary. The speaker will get repaired if needed or re-coned where necessary.

In short, your chassis will be returned to you in full working order with a full 30 day warranty on the work I perform. Keep in mind that the chassis will retain many of it's 60 or 70 year old parts which could fail at some time. These items will not be warrantied. I do, however play (burn in) radios off and on for days to help eliminate any gremlins that may appear after the repair is done. This helps eliminate any problems that could come up and I can take care if it right away.

Click on my eMail address (above) to contact me directly

My Repair Resources:

books on old radios

An extensive library of original manufacturers' repair manuals and parts manuals are absolutely essential.

old radio tubes

Original tubes, capacitors and repair parts are a finite resource. But they're vital to a quality repair or restoration.

I maintain one of the area's finest technical libraries of original, vintage manufacturers' repair manuals, in addition to hundreds of the corresponding parts lists and bulletins associated with each vintage manufacturer and its various lines

I keep a huge inventory of authentic, original equipment, vintage tubes, capacitors and other parts to provide the most authentic, accurate and precise repairs and restorations possible.

I maintain contact with a vast network of other collectors throughout the world. We readily share whatever information we can provide to each other regarding a specific brand or model. If I can't find an immediate source for a part or instruction, I can usually obtain at least an answer from the network within twenty-four to forty-eight hours in most instances.

There were literally hundreds of thousands of replacement tubes, caps and other critical repair parts available as late as the 1970s, but they're becoming harder and harder to find and obtain.

I often spend as much time finding reliable stores of replacement tubes and supplies as I do in researching specific models and their details. But every minute spent on research pays big dividends toward a quality restoration or repair.

My Repair Facilities:

I have an extensive, two-story, climate-controlled, moisture-controlled warehouse, parts store, and repair shop on the premises. I employ the finest hand tools and equipment currently available for my repairs and restorations.

Examples of my Repairs:

Philco Baby Grand radio

Here's one of my own 1932 Philco Baby Grand Cathedral Table Radios

Zenith Walton Tombstone radio

1937 Zenith 'Walton's' Table Model 7-S-232

I'll be posting some examples of both past and present projects from month to month, from links you'll find here. I treat each of my projects as if they're my own--at least until the last moment that I return them to their owners. I suppose it's like taking in a foster child until that moment they find a permanent family. That's as good an analogy as I can think of, in any case.

And yes, it's hard to let some of them go. But I know in each case that they'll be entrusted back to the owners that care for them the very most.

The common denominator in all of these fine examples of early to mid-20th century engineering is the incomparable sound that only a tube-powered radio or amplifier can impart. Despite all of the extraordinary technological advances in transistor and micro-circuitry technology dating from the mid-20th century until today, nothing yet approaches the full, mellow sound from a tube-powered radio chassis.

Sadly, the means of comparing that incredible, robust sound to today's artificially shaped sound technology remains a finite resource. But if you truly love that tube-powered sound, there's only one real way to obtain it.

One thing's for sure. Once you hear the difference there's no turning back.

You're hooked for life.