Recently acquired Collins 75A-4 receiver from the estate of a deceased ham. It works, and the condition and appearance is great im my opinion. The serial number is 492. Does this low number in the case of this receiver make it more or less valuable?
Fred WA4EQG
75A-4
Generally speaking, the higher serial number 75A-4's are more sought after than the lower numbers. That is because the factory incorportated a number of changes over the production life of the receiver. The highest serials are in the 5000's.
One significant change was the use of a 4:1 dial reduction mechanism instead of the direct drive 1:1 tuning dial. Many 'A-4 owners updated their receivers with the newer tuning mechanism, so lots of early model units have the 4:1 dial. I owned one in the 200 range that had been retrofitted with the later dial. If your receiver does not have the 4:1 dial it will take a significant value hit.
Another important mod was the addition of a shunt feed circuit for the mechanical filters to remove the possibility of the B+ ruining a filter in the event of a capacitor failure. It really isn't prudent to operate an early 'A-4 without ascertaining whether this mod has been accomplished, particularly now that the internal components have at least 50 years on them! Again, many owners did this on their own. The factory began incorporating this circuitry in the mid-3000 range if my memory serves me. There are a number of other mods Collins released as service bulletins. Collectors usually value the early models more that have had these mods performed (correctly).
While well thought out and expertly crafted internal circuit improvements may not hurt, or actually enhance, the value of this machine, faded dials, cracked knobs, dents, scrapes, scratches, extra holes, knobs, or switches are anathema to the collector. While all these problems can be corrected with an investment of time and effort (and likely a liberal application of dollars), external appearance of originality is important.
As you no doubt realize, the 75A-4 is a real benchmark receiver and was truly a revelation in its heyday, the mid 1950's. The dial calibration and selectivity, although poor by modern standards, were unmatched by its contemporaries. It was quite a novelty back then to actually know what frequency that you were operating on! Even now this radio is great fun to operate and still acquits itself quite well 50+ years on.
One significant change was the use of a 4:1 dial reduction mechanism instead of the direct drive 1:1 tuning dial. Many 'A-4 owners updated their receivers with the newer tuning mechanism, so lots of early model units have the 4:1 dial. I owned one in the 200 range that had been retrofitted with the later dial. If your receiver does not have the 4:1 dial it will take a significant value hit.
Another important mod was the addition of a shunt feed circuit for the mechanical filters to remove the possibility of the B+ ruining a filter in the event of a capacitor failure. It really isn't prudent to operate an early 'A-4 without ascertaining whether this mod has been accomplished, particularly now that the internal components have at least 50 years on them! Again, many owners did this on their own. The factory began incorporating this circuitry in the mid-3000 range if my memory serves me. There are a number of other mods Collins released as service bulletins. Collectors usually value the early models more that have had these mods performed (correctly).
While well thought out and expertly crafted internal circuit improvements may not hurt, or actually enhance, the value of this machine, faded dials, cracked knobs, dents, scrapes, scratches, extra holes, knobs, or switches are anathema to the collector. While all these problems can be corrected with an investment of time and effort (and likely a liberal application of dollars), external appearance of originality is important.
As you no doubt realize, the 75A-4 is a real benchmark receiver and was truly a revelation in its heyday, the mid 1950's. The dial calibration and selectivity, although poor by modern standards, were unmatched by its contemporaries. It was quite a novelty back then to actually know what frequency that you were operating on! Even now this radio is great fun to operate and still acquits itself quite well 50+ years on.