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G8MNY > TECH 04.03.09 01:00l 42 Lines 1605 Bytes #999 (0) @ WW
BID : 19630_GB7CIP
Read: GUEST
Subj: HITACHI V-1050 SCOPE info?
Path: IZ3LSV<IK2XDE<F5GOV<F4BWT<VE2GPQ<VE3KPG<GB7CIP
Sent: 090303/2324Z @:GB7CIP.#32.GBR.EU #:19630 [Caterham] $:19630_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EU
To : TECH@WW
By G8MNY (New Mar 09)
(8 Bit ASCII Graphics use code page 437 or 850)
Hi & thanks for reading,
I bid for this faulty 100MHz dual beam scope at a club junk sale & won it
for only œ1.50. It had no handbook so I had to fault the "no display" problem
blind. I found a short circuit 22V zener in the complex brillance circuit, & I
also replace the EHT shroud that was missing, obviosuly someone had been there
& gave up on it.
There was also a poor blanking fault & the brilliance altered the focus a bit.
This proved to be a PNP again on the EHT unit, a grounded base transistor
blanking amp that was a short & had no gain, hence the current drain on the
supply to alter the brilliance & defocus.
ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿Btrig
³³~~~~~~~~³ o' o ,ø ³
³³ ³ o : (O) o ³
³³ ³ ù (o) o o ³
³³________³ o ú -- -- ³
³= -- ³
³ (o) o. (o) = -- ³
³o .o ù|ù o. o o o³Atrig
ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
Y1 Y2 Earth
Well it now works quite well, but I also found there was a fault in the dual
timebase mode control, as there seems to be no difference between A timbase &
A intensified with B timebase. Tracing the mode track from the switch via diode
gates, the his proved to be a non soldered through plated hole not bridging
both side of the PCB tracks together on the trigger board, must have been like
that since new!
Any information on this old piece of testgear would be very welcome.
Why don't U send an interesting bul?
73 De John, G8MNY @ GB7CIP
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