Tag Archives: Icom IC-R72

Icom IC-R72: a repair story

Icom-IC-R72-Front-Mehdi-AsgariIn this post I’m going to tell you how I repaired my Icom IC-R72 receiver. Although it’s about a specific device, the logic and methodology applies to all radios.

I bought an Icom R72 from a friend for about $200. At first, I just checked 7.0MHZ (40 meter band) and 21.0MHZ (15 meter band) and it was OK. After some time, I tried to listen to some ham radio on 20 meters (14.0MHZ) and it was deaf! I checked everything: antenna connectors, balun…everything.

With some trial and error, I found out that it was deaf from 11-15 MHz. With the help of the members of “Icom R72” Yahoo Group, I found one of the usual suspects: bandpass filters’ switching diodes.

I took a look at the service manual and apparently this radio uses multiple bandpass filters  for different  frequency ranges.


As you see in the above picture (grabbed from service manual), one of the bandpass filters is for 11-15 MHz range–that’s the range where my radio was deaf.

Note that there are multiple ways to test that a radio is deaf at a frequency. One of the simplest ways: connect an antenna or even a long wire to the antenna socket of radio. The noise level should increase; if not, there’s a problem.


After testing diodes with a multimeter, I found out that D31 is faulty. Almost all multimeters have a diode-test functionality.

I replaced it. The original diode was 1SS53, but I used a 1N4148 which is very common and found everywhere. Now I have a working radio! 🙂

If you have a radio that’s deaf at a frequency range, there is probably a problem in bandpass filters.

Here are some internal pictures of my Icom IC-R72:

IC-R72-Internal-IF-Stage-Mehdi IC-R72-Board-1 IC-R72-Board-2 Icom-IC-R72-Open

I should thank my friend and electronics mentor, Saeed (EP2LSH) who always helps me in my electronics adventures.

Mehdi Asgari, the author of this post, is a regular contributor to the SWLing Post. Mehdi lives in Tehran and is an active member of the EP2C amateur radio club.

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Guest Post: A Late Summer Visit to Howard Mills’ Radio Restoration

Many thanks to former VOA correspondent and noted DXer, Dan Robinson, for the following guest post:


A Late Summer Visit to Howard Mills’ Radio Restoration

-Dan Robinson

The end of summer is a wistful time, as we begin to mourn the passage of warm days and anticipate the arrival of autumn.

For those of us in love with shortwave, even in these waning days of HF broadcasting, August brings changes in propagation that herald the approach of improved reception, thoughts of getting antennas in shape, and preparing receivers for the new DX season.

It’s also a time when Hamfests are winding down for the year — for me, it’s still great fun to attend these and see what equipment is available.

A few months ago, I and fellow Washington, DC area SWL Dave Malick took the opportunity to visit a couple of Hamfests. At one of these, in Berryville, VA, I ran across someone who over the years has become somewhat of a legend in the field of radio restoration — Howard Mills.

Howard lives in rural West Virginia, at a point about equidistant from Harper’s Ferry and Sheperdstown. That’s about an hour or so from DC and the immediate Maryland suburbs. From DC, you drive out Rt 270 to Frederick, Maryland and then up Route 15 and 340.

It’s beautiful country — on the way you pass through small towns, past farms, and in late summer, roadside stands selling huge ears of corn and about every type of vegetable, along with peaches and apples of every type and size.Rack mounted equipment

Back in the late 1990’s I first became aware of Howard Mills when I brought my Collins 51J4 to him for refurbishing.   Howard is one of the few persons remaining in this country capable of going through classic tube receivers from top to bottom.

A visit to Howard is an experience everyone should have at least once in a lifetime. Restoration activities take place in the lower/ground level of his home.

Outside there are some amazing antennas, long wires, and beams which support both his amateur radio and receiver activities.
DSCF7558Under a porch, covered in tarps, are some of his latest equipment and parts acquisitions, from thousands of tubes to some of the rarest radios and transmitter items one may ever see.

Howard at his home in WVA

Inside, you find a wonderland of receivers. You name it, Howard has it. In racks, there are specialized Beckman 51J4s, SP-600s, AR-88s and R-390/As, Eddystones, and others. In another room, you see some of the most beautiful, and collectible and valuable, American and foreign-made radios dating back to the earliest days.

Rare Eddystone

On tables in one portion of the basement of Howard’s place, you find several R-390s in various stages of refurbishment. One, he notes (probably among his “keepers” ) was found still new in its original crate (how I would love to have that one!).

On the day Dave and I visited, the purpose was to pick up one of the most beautiful R-390s I have ever seen — a Capehart that was refurbished by Howard in 2007 and placed in a custom cabinet, complete with an easy-left-off top, similar to the HQ-180 design. This black beauty is now sitting in my shack at home.

R-390A Capehart

Howard has been at it for many decades, as I said. A conversation with him is a voyage through radio history, punctuated by references to a range of major radio manufacturers. He clearly loves what he does, though one wonders how much longer he will be at it.

Howard emphasizes by the way that his work is in restoring TUBE radios — he doesn’t get into solid state. There are a few well-known receivers in his place — I noticed an ICOM IC-R72 and a JRC NRD-535– but most of what you see are the classics that we have all come to know and love.


His primary specialty appears to be the 51J series. A link to him on the Collins site notes that his main focus is on A line equipment, J series, and 32V series, but he is certainly capable on a number of models, including as I saw, HQ-180s and AR-88s (http://www.collinsradio.org/howard-mills/)

I was able to take some photos of Howard’s operation and offer them to SWLing Post readers here. At this point, Howard remains in business. He has had customers from all over the U.S. and I assume around the globe.

For each refurbishing job, Howard provides an extensive print out of every single modification and component replacement he does, along with the results of sensitivity and calibration tests done for each set.

Please do note that Howard makes clear that basically as long as it takes him to refurbish a radio — is as long as it will take.   If you give him one of your radios, you basically agree to it being with him for several months if not longer. He does have a backlog.

R390A New

Things like sandblasting front panels for R390s (I am not certain to what extent he does this himself or out-sources this particular aspect) also takes time.   And the detail with which he approaches a breakdown of an R390/A, evidenced by the sets I saw in process, is quite extraordinary and time-consuming.

Howard gets mostly superb reviews from those who have used his services. If you look him up on the Internet, and he has time for you to visit, it’s an experience you will always remember, though it’s not that I would suggest a crowd descend on him.

Hope everyone enjoys the photos — I had intended to get this article to Tom much sooner than October. Keep in mind, of course, that though Howard is one of the last to do this kind of work, there are a few others, including Chuck Rippel in Virginia.

We are indeed lucky to have anyone still doing this work. We know they do it not just as a business, but out of a love for this wonderful old equipment.

Photo gallery

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Many thanks, Dan, for taking us on this virtual tour of Howard Mills’ collection and workshop!

Your Capehart R-390A is absolutely gorgeous; Howard, no doubt, brought it back to mint status through loving, considerate restoration. What a great addition to your collection, Dan.

Thank you, again,  for sharing your guest post.

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