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Old 13th Feb 2018, 4:26 pm   #29
MrBungle
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Join Date: Jun 2016
Location: London, UK.
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Default Re: HT / filament transformers from Aliexpress

Quote:
Originally Posted by Bazz4CQJ View Post
The original design (1940's) actually uses a 240V transformer, with a valve rectifier and then a voltage regulator tube to get down to 150V (the required anode voltage is only ~105V). I'll replace the regulator with zeners just to save space.

My 450MHz digital frequency counter (~£8 inc p&p) arrived from China a few days ago and the quick tests I've done so far are all good. Mostly, my budget-buy Chinese cheapies have been very satisfactory.

B
Zeners also probably consume a lot less power than the valve rectifier and regulator tubes!

I bought one of those but I couldn't get it to stop turning off every 30 seconds or so. This turned into a journey of despair buying three different second hand brand name counters until I found one I really liked.
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