- - - - - For a 91 year old radio.
Around 1925 Electronic Research Laboratories (ERLA) made a series of reflex receivers with crystal detectors under the model name "Superflex". These were 3, 4 and 5 tube kits, though they had also made 1 and 2 tube kits as well.
Our subject is a "Superflex Cir-kit-5. There are several unique things about this radio. First, it worked when I got it after being stored for decades. Second, it was assembled in a reasonably competent manor. This is not, on average, true. Third, the shipping container was still with the radio.
Now, these kits had some unique parts, There was the sealed crystal, to be used as a detector. And there are the little 2 and 3 way splices which were just clamps held together with a screw. This eliminated the need to solder anything and was significant in the assembly both surviving and working in the first place. Bad solder joints are the rule rather than the exception in these early kit radios. Just to back up this assertion, of the last 4 kit radios I have acquired, 2 probably never worked, 1 might have worked poorly, but this one still worked well.
Yes, it worked well, for a reflex circuit that used a crystal detector. It worked well if you sat close enough to the radio to fiddle with one or two controls every couple of minutes. Otherwise your signal would slowly degrade to garbled words or a squeal. The radio is very sensitive to slight changes in cathode temperature and/or changes in B+ voltage, less so on strong local stations. DXing required a dedicated operator. Otherwise it was loud and sensitive with push-pull output.
Our subject is a "Superflex Cir-kit-5. There are several unique things about this radio. First, it worked when I got it after being stored for decades. Second, it was assembled in a reasonably competent manor. This is not, on average, true. Third, the shipping container was still with the radio.
Now, these kits had some unique parts, There was the sealed crystal, to be used as a detector. And there are the little 2 and 3 way splices which were just clamps held together with a screw. This eliminated the need to solder anything and was significant in the assembly both surviving and working in the first place. Bad solder joints are the rule rather than the exception in these early kit radios. Just to back up this assertion, of the last 4 kit radios I have acquired, 2 probably never worked, 1 might have worked poorly, but this one still worked well.
Yes, it worked well, for a reflex circuit that used a crystal detector. It worked well if you sat close enough to the radio to fiddle with one or two controls every couple of minutes. Otherwise your signal would slowly degrade to garbled words or a squeal. The radio is very sensitive to slight changes in cathode temperature and/or changes in B+ voltage, less so on strong local stations. DXing required a dedicated operator. Otherwise it was loud and sensitive with push-pull output.
I had always thought that one of the first instructions in these kits was "go out and cut the appropriate sized board to mount your components on". Not this one. If you look closely in the center of the empty tube socket, the board is stamped "SOCKET" indicating parts placement. ( CKET is visible )
The little red labeled reflex transformers are also cool. The single blue one just helps in antenna coupling and only 3 of the 4 contacts are used. Almost all of the parts are marked ERLA.
So, now where am I going to keep the box?
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