[R-390] T-195 help needed
Norm - WA3KEY
norm at wa3key.com
Mon Jul 19 11:15:27 EDT 2004
Hi Gang,
I recently found a nice, clean T-195B transmitter and am having
difficulty getting it going. Perhaps someone on this list with
T-195 experience can give me some pointers. Here's a list of
things I've confirmed so far:
Low B+ (OA2 lights on key-down) and filaments
High B+ (measured at plate of PA tube)
All tubes checked good on a TV-7D/U
PTO oscillator output at 1.5MHz
Rear and cooling fan interlocks closed
Re-seated all connectors accessible without removing modules
There is no power output ... not even one milliwatt. If I wrap
an insulated pick-up wire around the antenna binding post (with
the 50 ohm output still connected to a dummy load) a very weak
signal can be heard about 10-20db down from wrapping the lead
around the oscillator tube.
Everything mechanical seems to function properly and the antenna
coupler goes through the motions until the red tuning indicator
lamp comes on. When going key down with a mic or using the "test
key" in CW, I can hear additional blower noise and the current
drain increases to about 20 amps from the 9 amp standby current.
(Remember this is a "B" with transistorized power supply.)
Although I can't test the 4X150D's, the filaments are OK and
swapping the PA with one of the modulators made no difference.
I checked with the rig's former owner and he confirmed it was
working fine before being placed in dry storage about 2 years
ago. One odd thing I noticed is that the transmitter won't power
up unless I rotate the "service selector" switch all the way
around to "remote" at which time I hear a click and the dial
lights blink. Then if I go back to any other position (except
"off") the transmitter will power up.
Any trouble shooting pointers on this rig will be greatly
appreciated. I'd also like to know if the transistor power
supply from a T-195B can be transplanted into a regular T-195
without additional modification.
I subscribe to this list in digest form, so your reply by
e-mail will be faster. Thanks much for reading this post.
73 de Norm - WA3KEY
norm at wa3key.com
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