----- Original Message ----
From: "gandalfg8@..." <gandalfg8@...>
To: loopantennas@...
Sent: Sunday, May 6, 2007 1:02:40 PM
Subject: Re: [loopantennas] Wellbrook ALA1530 - corrected
In a message dated 06/05/2007 17:22:12 GMT Daylight Time,
nonlinear@rogers. com writes:
Is it absolutely confirmed there were only 2 transistors in the autopsy?
best wishes
Paul
At first I had some doubts as the posted photos seem to show more than two
transformers but related postings do indicate two. Originally at least it
would seem that the transistors used were TO92 ZTX337s.
------------ --------- --------- -----
Hi Paul
Are we confusing transformers and transistors? :-)
PVB==> Dear Nigel definitely no-- I remember the two transformers the blue devices
btw not sure there was not inductors also , cannot remember
I remember now sort of 4 blue devices will hunt down the pictures again and look, I know I filed them
Pat confirmed two transistors and two transformers.
PVB:==> OK
Initially though the rather fuzzy photos in the group photos section seemed
to show a couple of can enclosed transformers still on the board with what
might have been another one detached.
Pat, if you see this, I wouldn't mind higher res copies of those photos if
you have them, and wondering if you managed to trace the circuit from the
remains?
PVB:==> good request Nigel!!
thanks so far
BTW:==> the reason I asked about the extra transistors is that if used in parallel can reduce noise level by factor of 1.414 ie SQRT(Np) where Np is the number of devices in parallel
so if the transistors are not too costly it is a practical way to reduce noise level
therefore under John Crabtree's analysis the transistors would be operated at 60/2= 30 ma which may in some ways make more sense
from heat dissapation perspective
{ although this transistor is rated 400 ma needing for sure at this level a heat sink but we know max current is of the order of 120 ma}
very best
Paul
