[Drake] Mea Culpa - Drake C-Line and TR-C DC owners.

[Garey Barrell]

An error in the C-Line and TR-4C CDs has been brought to my attention.

The error is in the T-4XC and TR-4C Relay Replacement Sheet.  It SHOULD read as follows.....

>>>>>>>>>>>>>.<<<<<<<<<<<<<

Replacing the T-4XC Relay

The "correct" replacement relay is the P&B (Tyco) R10-E1-Y4-V2.5k, same relay
used in the "late" T-4XC and TR-4C, which IS available from Mouser and Digikey
among others. Currently about $25.

If your old relay is a Varley with a 15k coil, you need to look at the socket for V19, the
6FQ7 (or 6EV7). If there is a 1.5k, 1W resistor connected between Pin 1 and Pin 9,
just plug in the new relay. If there is NO resistor, remove the wire connected to Pin 1
and move it to Pin 9, add a 1.5k, 1W resistor between Pin 1 and Pin 9, and plug in
the new relay.

The 15k ohm coil relays were failure prone, primarily because of the very fine wire
needed. The bobbin would swell, especially in humid conditions, stressing and
breaking the wire. This is why T-4XC's that have been stored in the garage for a
while often have a bad relay! The 2.5k ohm coil of course uses considerably larger
wire.

>>>>>>>>>>>>>>.<<<<<<<<<<<<

I don't know where the reference to Pin 6 came from, it's not on any of my reference notes.  Guess 
it just goes to show that you can never have too many (enough?) people proof-read your writing....

I'm very sorry for the error, and will be happy to send a corrected PDF for any who wish to add it 
to their CD.  Some CD writing software will allow you to add files, some will not.

-- 
73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>