Beomaster 900K - Refurbishment

2 replies
M(
Offline
machineage (archived2)
Bronze
Posted September 13, 2017 at 23:35 GMT
#2252996

Hi all!

So I recently acquired a Beomaster 900K type 2232. I would like to carry out some refurbishment work on the unit - electronically as well as cosmetically. It's currently working but does have issues. So a few questions if I may 🙂

1) The bulbs have all failed. They are listed in the schematics as 6.3v / 0.3a for the dial and 19v / 0.1a for the stereo indicator. Would 6.5v / 0.3a bulbs be acceptable for the dial and 24v / 0.125a for the stereo indicator?

2) The unit sounds OK but bass distorts at reasonable volume level - any pointers as to what may be causing this?

3) The FM scale reading is way off from broadcast stations. How would I go about re-aligning it?

4) What are the usual recommendations with regards components to replace and any other things I should check / look out for?

Many Thanks!

DI
Offline
Dillen
BronzeModeratorFounder
Posted September 14, 2017 at 06:43 GMT
#2252997

1.
For the dial, yes. I like to fit 7V 0,3A for increased lamp life.
For the MPX lamp, no. The circuit is already a bit on the weak side.

2.
Speaker cones cracked?
If not - put a scope to the signal path and see where the distortion is introduced.

3.
If it's off by the same amount across the dial, push the pointer along the string to suit.
If not, you must align the tuner, IF etc. according to the servicemanual.

4.
IF transistors.
Alignment of MPX/stereo decoder (if fitted).

Martin

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