[TenTec] QSK or not?

[GARY HUBER]

I operate QSK and have the past thirty years using TenTec equipment.

One reason given by others for not running QSK is that the relays wear out sooner in the transceiver and amplifier.

from http://www.ad5x.com/images/Presentations/QSKals500als600RevA.pdf 

How Long will the Relays Last? 
What kind of life can you expect from the relays? The relay life is specified at 100 
million operations minimum at 36,000 operations/hour. The service life increases as the 
operations/hour decreases. So let’s use the standard PARIS text that is used for 
determining code speed. 

PARIS has 10 dits and 4 dahs = 14 relay operations/minute at 1 WPM. 

Assuming an average of 25WPM code speed, you would have 360 relay operations per 
minute. So, 100 million operations = 4630 hours. Now you normally operate 50% 
transmitting and 50% receiving during a QSO, so your relay operating time should 
double to 9260 hours. There are 8760 hours/year, which means you could operate 1.057 
years at 25 WPM before the relays exceeded their lifetime spec – IF you operate 24 
hours/day! But when you operate, you are probably listening more like 75% of the time 
and in a QSO 25% of the time. So this says that your relay operating life will be over 4-
years if you operate 24 hours/day. So what do you normally average in operating 
time/day? I bet it is not more than about an hour/day. But let’s say you average 4-
hours/day of operation (i.e. you are not married and have no kids, you don’t shop or eat
or sleep much, and you don’t hold a full-time job). So the relay life will extend to about 
25 years! The bottom line - Don’t worry about wearing out the relays anytime soon.

73 ES DX,
Gary – AB9M    -...-.-