[Amps] Equalising resistors with HV diodes

[R.Measures]

On Sep 21, 2004, at 1:11 AM, peter.chadwick at Zarlink.Com wrote:

>
>
>
>
> Traian makes a very good point. Some 35 years ago now, I was at a 
> company
> doing MF SSB maritime transceivers. The  Buyer was instructed to buy 
> the
> cheapest transistors, and bought from Microelectronics in Hong Kong. 
> First
> problem was low drive - the 2N3866's were below JEDEC spec on DC Beta, 
> and
> we didn't bother trying to measure Ft. The reliability of the BC108's 
> was
> terrible - they didn't meet the published specification on Vcbo.
>
> And of course, it was all the fault of Engineering!!!!
>
> Somehow, this sounds a bit reminiscent of the horror stories of the 
> early
> 3-500Zs from the far east.....
>
The best one I've heard is way back when the Chinese were using glass 
with a high D-factor flux, when the 3-500Z would oscillate at c. 
100MHz, the glass around the anode stem would soften and a glass bubble 
would form on the vacuum side of the envelope.  Sometimes the glass 
bubble would pop.
>
Richard L. Measures, AG6K, 805.386.3734.  www.somis.org