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Old 3rd May 2021, 10:32 am   #20
dazzlevision
Dekatron
 
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,595
Default Re: Bush Dual standard chassis.

Quote:
Originally Posted by Heatercathodeshort View Post
1973 date code on that lopt Dazz.
I must admit I didn't find those plastic overwind Plessey transformers any better than the tar one.
Plessey were a superb company that supplied transformers and component parts to the whole of the TV manufacturers. That plastic overwind turned up in many chassis including the Thorn 850, Decca and many others including of course the later 640 RBM chassis, all of which we all know was not very reliable. The good bit, they were not expensive or difficult to replace.
I was never a great enthusiast for the RBM chassis introduced between the TV125 to the 640. probably just a sign of the times with those touchy hybrid models including the TV161GU that was a wolf in sheep's clothing! It's many years since I have seen any of that series. John.
Hello John,

I would agree that the Plessey version of the in-house made pitch covered Bush LOPTs were no better or worse than each other. However, when TVs using these were "pensioned off", I have found the Plessey versions usually still work when the TV is "woken up" again after many years of disuse. Looking at the relevant RBM service manuals, it seems that their production began fitting Plessey (or RBM made) LOPTs from the all-valve TV141 and hybrid TV145 mono chassis era.

The TV141 all-valve chassis was, in essence, just a rearranged version of the TV135R one. The TV161GU was, electrically, very similar to the RF & IF stages of the TV135 hybrid chassis - but without back level correction - big mistake!

I definitely agree that the period from the TV135R until the arrival of the RBM A640 chassis, was not one of RBM's "finest hours"! They were driven too hard by trying to keep the selling price competitive.

Last edited by dazzlevision; 3rd May 2021 at 10:41 am.
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