Panasonic RF-728 AM/FM Analog Portable
The Panasonic RF-728 is a cool-looking AM/FM all-analog portable radio manufactured around 1965. It was recommended to me by a reader who is fond of this model and thought I should check one out. I have been very impressed by several Panasonic radios such as the RF-2200, RF-4900 and RF-B65 and although this was clearly a much less sophisticated model than those, I thought it would be interesting to see what a mid-line AM/FM radio from Panasonic’s heyday might be like. I set up an eBay search and found one in short order at a good price, mostly because its cosmetics were not top grade…at this point I was mainly interested in seeing what the radio was like as opposed to making a display item out of it. This is part of my continuing look at several vintage all-analog portable radios.
The RF-728 is a medium size AM/FM design featuring a 2 ½ x 4″ speaker, a Hi-Lo Tone Switch and a dial light. It runs on 4 AA cells and has a built-in 120 volt AC power supply . It measures 8.13 x 4.13 x 1.83 inch / 207 x 105 x 46 mm and is heavy and solid in the tradition of the best old radios. No plasticky feel here. It also sports a large ferrite rod antenna of approximately 7” which is longer than most portables…the potential is there for great AM sensitivity.
When the radio arrived it did indeed have cosmetic issues…the rather typical paint spots and more importantly a missing chrome trim piece on the left side which, although unattractive, is luckily not that apparent when viewed from the front. That was not shown in the eBay pictures…nothing new there. I decided to hold onto it anyway because I still wanted to judge its performance and if it turned out to be a radio I liked I could keep it as a parts donor set and look for a nicer sample. Little did I know it was more likely to NEED parts rather than to donate them.
The First Inkling of Trouble: I always put batteries into a radio I just acquired to see what kind of operational shape it is in and right off the bat I discovered the radio was totally dead…nothing was happening whatsoever. Removing the back cover, I found a broken battery box. One end was broken right off so the batteries couldn’t work at all (and of course the radio was advertised as “working”). Perhaps the seller was using an AC cord which was not included???
Although such things are usually not repairable, I tried the amazing Loctite Plastic Repair glue which has often amazed me in the past and it actually worked…the battery box seems as good as new although I will always treat it with kid gloves…I could probably find a generic replacement if needed but for now it is OK.
With the back cover removed I discovered a bigger problem: The AM ferrite rod was broken in half. Replacing it would be more than likely be tricky unless I bought another RF-728 so I decided to see if it could be glued back together. Many folks don’t realize this but if a broken ferrite rod has a clean break and is glued back together with a perfect fit it will function as well as new. When I first learned this years ago I found it hard to believe but over the years I have repaired a few broken ferrite rods and they have worked every time. As I said the key is a good fit, so I started by experimenting to see how the pieces fit together…they fit like a glove with only a small missing chip which I judged to be insignificant. In fact, I found that it would hold itself together with a rubber band and it seemed to be working normally at this point, so I used Super Glue and left the rubber band in place as an added precaution. I left it until the next day and have left the rubber band there as well…it can’t hurt. I did a general check and everything seemed to be working normally but the dial calibration was a bit off which is often a good indicator that an alignment might be needed.
Finally Working: Now I could see what this radio could do. Initially its performance was OK but unremarkable…its AM and FM reception were average, both rating ** on the AM and FM Mega Shootout lists which is good for a typical mid-sized 1960’s AM/FM portable. FM was typically broad with much less selectivity than today’s portables but it had reasonable sensitivity. I had found a copy of the original service manual on eBay so I proceeded to do a complete alignment and the difference was well worth it. The AM went from ** to *** stars with noticeably improved sensitivity and I was able to get the dial calibration just about perfect across the band. Now the AM was fairly sensitive and selective and being a true analog design was a true pleasure to band scan with. All my usual daytime signals were there and at night the dial was full of signals…the nice illuminated slide rule dial is a pleasure as well. A small passive loop couples well to the radio and greatly increases sensitivity as you would expect. FM dial calibration improved as well as sensitivity but the selectivity stayed about the same as you would expect…modern FM’s are simply much more selective. But I had bought this radio for AM and I am very happy with it.
Conclusion: Although not a super radio by any means the Panasonic RF-728 is well made and solid and is quite heavy for its size. It has the wonderfully smooth and natural tuning characteristics many of us love about old analog radios and although its sound is rather plain it is nevertheless is a nice medium size radio to use and I like its looks and solid feel. I think I’ll keep this one and I thank the reader who recommended it to me.