"Anonymous" wrote in message ...
I need to replace the T/R relay on an FT480R.
(Intermittent Rx, curable by a quick blip on TX)

I don't have an exact replacement, so I'll use a
Varley 12V relay, with suitable mods to the driving cct,
and dangle the relay in the space behind the front panel.

Is there a knack to removing the main board without first
unsoldering the numerous connections? (i.e., can it just
be a tedious job, or must it be downright finicky?)

There is a second pair of change-over contacts on the
relay, but with both outputs wired together...this would seem
to suggest some form of muting effect that deals only with
the T/R or R/T changeover period. Any ideas?


From the circuit diagram:

The relay switches two things:

Antenna (Rx/Tx)

13.8V to the Tone unit.

One side of the relay coil is to the 13.8V internal rail, other side is to
the Main Unit and, unless it is very convoluted, isn't connected to either
set of relay contacts nor do the two sets of contacts seen to be connected
to each other.

I've done one of these before and, as I recall, "pin for pin" relays were
available- I think Farnell.

"Brian Reay" wrote in message
...

From the circuit diagram:


Which I can scan the relevant section of and place on my website for
download.

"Brian Reay" wrote in message
...
"Anonymous" wrote in message
...
I need to replace the T/R relay on an FT480R.
(Intermittent Rx, curable by a quick blip on TX)

I don't have an exact replacement, so I'll use a
Varley 12V relay, with suitable mods to the driving cct,
and dangle the relay in the space behind the front panel.

Is there a knack to removing the main board without first
unsoldering the numerous connections? (i.e., can it just
be a tedious job, or must it be downright finicky?)

There is a second pair of change-over contacts on the
relay, but with both outputs wired together...this would seem
to suggest some form of muting effect that deals only with
the T/R or R/T changeover period. Any ideas?

From the circuit diagram:
The relay switches two things:
Antenna (Rx/Tx)
13.8V to the Tone unit.
One side of the relay coil is to the 13.8V internal rail, other side is to
the Main Unit and, unless it is very convoluted, isn't connected to either
set of relay contacts nor do the two sets of contacts seen to be connected
to each other.
I've done one of these before and, as I recall, "pin for pin" relays were
available- I think Farnell.

You're looking at the wrong cct diagram. Read my lips, "Main Unit"

How rude! He was only trying to help you.

What a strange way to maintain standards.

"Anonymous" wrote in message ...
You're looking at the wrong cct diagram. Read my lips, "Main Unit"




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