CQT-1110 Transistors in Lafayette HA-250 Amp

[Scott Johnson]

You should have about 600VDC B+ for those tubes, and if I were a betting man
I would say that either there is a bad leg in the rectifier bridge,or if it
uses a doubler, perhaps a diode or a filter cap. The transistors could
probably be any stout Ge PNP TO-3 case unit, such as an NTE-179. If the
supply is oscillating, I doubt, though, that it is a transistor or a
transformer.
73,
Scott

-----Original Message-----
From: Boat Anchor Owners and Collectors List
[mailto:BOATANCHORS at LISTSERV.TEMPE.GOV]On Behalf Of Rich Sahlender
Sent: Sunday, January 19, 2003 11:05 AM
To: BOATANCHORS at LISTSERV.TEMPE.GOV
Subject: CQT-1110 Transistors in Lafayette HA-250 Amp


Picked up an old Lafayette HA-250 Linear Amp recently which
I'm sure had been used by some 11m enthusiats but which I
recall using on 6m years ago. Sure enough, the manual shows
where to place the tap on the final tank coil for 6m use.

Nice simple circuit using a pair of 12jb6's in grounded grid
and a pair of CQT-1110 transistors with a unique (at least
to me...) toroid transformer used to transform a 12V DC supply
to a much higher B+ for the tubes. No indication in my docs
just what the B+ should be...

Initial tests show only 25w out with 5w carrier. I recall
getting closer to 45w out years ago. Checking final B+ shows
only 200v. I expected more and suspect an 11m good buddy has
damaged either the transformer or the CQT-1110's.

Anyone have any data on the CQT-1110's before I pull them for
testing? I get only one hit at an Asian site with a google
search... or anyone out there have one of these that can
confirm what the B+ and or typical power out should be?

tnx es 73 de Rich WA3WLH

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control -
http://www.tempe.gov/lists/control.asp?list=BOATANCHORS
To post - BOATANCHORS at LISTSERV.TEMPE.GOV
Archives - http://interactive.tempe.gov/archives/BOATANCHORS.html

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.asp?list=BOATANCHORS
To post - BOATANCHORS at LISTSERV.TEMPE.GOV
Archives - http://interactive.tempe.gov/archives/BOATANCHORS.html