GE / RCA "Super"radio. 12-603 "Super"radio clone. Realistic 12-650 "Long Range" radio. For that matter C-Crane, Grundig, etc. - all proposed as being the best "super" radio. But what does "super" really mean? Assuming you are only interested in AM, and only interested in portables - my most sensitive "super" is a Realistic 12-655, because it gets weaker stations clearer than anything else I own. But - its selectivity sucks (even with a narrow filter added). Nevertheless, I have some very good candidates for "supers" that might surprise you. I have used them for long range reception with excellent results. I will describe a couple of these sleepers here - you can make up your own mind whether or not they belong in the "super" category.
This deserves its own page ---- almost lost forever due to overuse, extensive modifications, poor decisions, and almost lost in a move - the heart of a classic Radio Shack Optimus 12-675 now has a new lease on life - and a new case!
But you would never know it - a construction article.
I don't frequent garage sales or estate sales very often. This radio really wasn't acquired at an estate sale, but was on the shelf at an antique store identified as part of an estate. At $10 or so, a solid looking portable would be hard to pass up - even if it needed some repairs. I needed a radio for work I could walk away from - being a victim of workplace bullying at the time. In case the jerk threw me out with just the clothes on my back, I'd lose a $10 radio. Fortunately for me, I was so good at what I was doing - fine tuning electronic compasses - that I not only won him over, but earned a line of recognition in National Geographic magazine for having one of the best Helmholz coil sets in the world. During the rough time, I was able to quarantine myself at a remote facility for nine months away from the jerk, and this radio was a constant companion. Not quite as good as a GE SR-2, but darn close on AM and FM! I listened to a low power Orlando station from nearly 40 miles away on FM. Clearly, there was something under the hood of this radio!
I was intrigued with the performance of this radio, knowing full well it was probably a re-branded GE or RCA. It has the simulated leather wrapped around fiber board case that was typical of the time, and I wanted to know the vintage. The back offered few clues:
Opening the back of the radio showed an ID tag with a little more information:
Sometimes the first two digits of the serial number gives the year. But I really doubt this radio is from 1978. But the production code number might indicated 1962, lot 92. Based on a lot of years doing this type of thing, I think 1962 is plausible as a manufacturing date. A look at the construction inside shows techniques from the 1960's:
A lot to digest here:
So there you have the story of radio number 1. Amazing unit, almost as good as a GE Super. Who made it? I still don't know for sure, but ONLY GE and Sony - as far as I know - can make transistor portables this sensitive without tuned RF stages. This means that both manufacturers have independently come up with a good converter design (oscillator and mixer combined in one stage). The converter is usually very noisy and ultimately the limiting factor on sensitivity, but it can be mitigated with a tuned RF stage that boosts the RF above the noise prior to mixing. So my guess is - GE. Is this a super? Definitely yes - because of sensitivity and selectivity. Somewhere between a GE SR and a Radio Shack 12-603. So if you call the 12-603 a "super clone", you'd have to include this beauty.
My daughter's first radio was a Radio Shack 12-603, not really a Superadio clone, but senstive enough in a medium fringe area to allow her to hear stations 50 miles away. As she got a little older and developed a bit of fashion sense, she discovered Mary Kate and Ashley Olsen. I didn't have a problem with that, the girls were making good, clean movies, and their clothing line was as durable as you can get. Certainly more durable than the Abercrombie, Hollister, and Ed Hardy that displaced them. They also made other items - a blow dryer which still works, and this radio:
My daughter used it as a CD player - before discovering iPods. The radio seldom got used - but I needed to grab a portable quick to go out in the garage and do some cleaning, and grabbed it. Tuning to the local 620 in Dallas - I overshot on the low end and heard KLBJ 590 from Austin at almost the same volume as a local station. What the _____? That's awfully good for a cheap boom box! A little exploration showed similar reception all over the band - this little boom box definitely has something under the hood!
Quickly finishing my garage task, and being by myself for a couple of hours - could I resist the temptation to put this thing on the bench to see what made it tick? I think not!!! The first thing I noticed was attention to ergonomics. One thing that really impressed me was the whip antenna, hidden away under the handle. IF you really needed it, it was there to use. But if you didn't use it, it wouldn't get broken off. Pretty slick idea!
With the whip extended, the "local" FMs (actually 30 miles away) punched right in. But so did a couple that were 50 miles away, and two rim shots 70 miles away. Wow! FM and AM both way better than most cheap portables.
Thoroughly intrigued, I began my analysis. Most modern radios have nice arrows pointing to the screws. Curious because they also have "no user servicable parts" labels. Go figure:
The screws removed, I removed the bottom of the chassis to have a look at what makes this radio special:
Four PC boards again, almost reminiscent of the four decade older Ward's radio. In this case, though:
The radio board is really spread out. As you see it in the photographs, it is actually after an initial round of modifications. I had used the clamp for the existing 2 3/4 inch rectangular bar and rounded it to accent a broken piece of a round ferrite bar. I had also done my ceramic filter mods to the board, but more on that below. Suffice it to say, I was more than impressed that a 2 3/4 inch ferrite bar was bringing in stations so well! The one a little bit longer worked even better!
Radio quickly re-assembled for my daughter - and in a flash it is 4 years later, my daughter having moved on long since to iPod docking radios (which have dismal performing radios). The MKA unit is MINE!
Let's look at the RF portion of the radio board:
The radio is based on an LA1824, which I have seen in many other radios. I have one in a Time magazine premium giveway radio - you subscribe you get a radio. It's performance is crummy - and I know why. It is NOT the fault of the LA1824, which - as my experience here shows - is fully capable of making some darn good radios. There are very few external components required, in comparison to the Ward's radio above. You need:
And you have the RF part of an AM FM radio. In the case of this design, they threw in an extra IF can on both AM and FM. I did substitue a 150 kHz FM ceramic filter for the one on the board, it didn't help all that much. I suspect the original was 180 kHz. Surprisingly, neither did the AM ceramic filter. They must have had a pretty good one on the board already, but this one did improve selectivity. It also made the radio a bit harder to tune, but that is not a major consideration.
Having already done the IF, I wondered how much improvement I could get if I put in a bigger ferrite bar. The case size of the radio is huge - there is plenty of room! I quickly located a suitable plastic bracket and a screw on the PC board - put the bar through, aligned and ---
What a difference! Almost as good as a GE Superadio - wow! This one is definitely a "keeper". Not the most sensitive radio I own by a long shot, but much better than a Radio Shack 12-603, so if you include it in the super category, you definitely have to include this one.
So what about that little "Time" radio? I firmly believe it suffers from crummy ceramic filters and I know for a fact the ferrite bar is very small. The FM whip is about 12 inches fully extended - how cute! This one - it is going to get re-packaged just to see if I am right, and the IC has the performance IF the parts around it are up to the challege. Stay tuned!