[Elecraft] OT about T-R switching with tube rigs vs. Elecraft

[N2EY@aol.com]

> The idea is you use the same antenna and switch
> it between the transmitter and receiver. With the > Drakes, and others, there is a small cable which 
> goes between
> the receiver antenna jack and a jack on the transmitter. The 
> transmitter has the large SO-239 (UHF) connector which then
> goes to the antenna, and when you transmit, the transmitter
> does the antenna switching (and receiver muting) back and
> forth. 

Many of the "matched pair" BA rigs are like that. But what you get is not "QSK" or "break-in", but rather "keyed VOX", sometimes erroneously called "semi-break-in". 

True QSK/break-in means you can hear the other guy between your own dits at any speed you use. Keyed VOX simply means you don't have to throw switches. A more correct name for "keyed VOX" systems is TATOO - TrAnsmitter Turner Onner and Offer". (I did not make that up - see QST about 1957).

I only know of one BA/tube rig that offered true QSK right out of the box - the Heath HW-16. Although called a transceiver, it's actually a separate transmitter and receiver in one box with a common power supply.
 
> Even with boatanchor pairs without such switching, there were
> external switchboxes (like Johnson's) available. I think MFJ
> even has them, now.

EFJ, B&W and a few others made "electronic TR switches" that protected the rx front end when you put the key down. They did not mute the rx, however, and all sorts of noises would come out of the speaker/phones unless you did something about it. A common trick was to use a highspeed keying relay, with the normally closed contact keeping the receiver alive and the normally open contact used for keying the tx. With a fast relay it works well. 

I used that method in a homebrew tx/rx pair in the early 1970s. A highspeed surplus relay could follow the bug at 40 wpm or better. Gave up on QSK in my later homebrew rigs because of the complexity of doing QSK with a transceiver. 

Another trick was to use two antennas and a neon bulb to protect the front end of the rx. 

The Ancient Ones were doing clean QSK all the way back to spark days. But it was always a custom, homebrew affair for hams until the HW-16 - then Ten Tec. 

The Elecraft QSK is right up there with the best of 'em - and it's standard!

73 de Jim, N2EY