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Old 4th Aug 2018, 10:45 pm   #2
Paul_RK
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Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
Posts: 4,247
Default Re: Hacker Sovereign models.

Hello Symon,

Well, some of the most apparent and consequential differences between the RP25, 25A and 25B happened between rather than at the change of models: for instance, the switch to all silicon RF transistors in the course of RP25 production, and the addition of a DC power jack before the change in model designation from RP25A to RP25B.

For the simplest answer to your immediate question, though, the RP25 became the RP25A with the change of FM tuner from type T304 to T309, and the RP25A became the RP25B when the FM IF board changed from one employing all discrete transistors to a board using the TAA920 IC.

The Sovereign III's history was quite complex too, at least as regards cosmetic options, with at least seven variants coming to mind:

Battery-only RP72, tunable only to 101 MHz
Early RP72MB, tunable to 101 MHz
Later RP72MB, tunable to 104 MHz
Black dial RP72MB, tunable to 104 MHz
"Jade" RP72MB in green suede, tunable to 104 MHz
Rosewood Sovereign RP721MB, again with black dial, tunable to 104 MHz
Golden Sovereign RP722MB, tunable to 104 MHz.

And the Sovereign IV exists in Maidenhead and Bournemouth versions: Bournemouth sets have a redesigned and plainer top panel which doesn't mention the "IV".

Corrections to my shaky memory would of course be welcome.

Paul
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