[TenTec] QSK or not?

Mon Mar 17 14:51:25 EDT 2014

Because relays don't cause receive overload problems when very strong 
signals saturate the pin diodes.

Carl Moreschi N4PY
58 Hogwood Rd
Louisburg, NC 27549
www.n4py.com

On 3/17/2014 2:14 PM, Kim Elmore wrote:
> Why use relays when we have PIN diodes?
>
> Kim N5OP
>
> "People that make music together cannot be enemies, at least as long as the music lasts." -- Paul Hindemith
>
>> On Mar 17, 2014, at 11:43, "Rick - DJ0IP / NJ0IP"<Rick at DJ0IP.de>  wrote:
>>
>> Different relays have different life cycles.
>> AND, keep in mind that this spec was specified for a relay when switching
>> between two STABLE STATES.
>>
>> If you run full QSK with the relay following the keying, sometimes the relay
>> is in transition when it gets a command to go the other way.  It must
>> overcome inertia and change directions. THIS IS ADDITIONAL WEAR AND TEAR on
>> the relay.
>> THIS type of operation is not considered in the specs.
>>
>> Also, when Phil wrote that paper on QSK, he was referring to the open-frame
>> relay used in ALL Ameritron amplifiers.
>> I guarantee you that this relay will  NEVER WEAR OUT  when trying to follow
>> QSK keying. . .
>> BECAUSE IT WILL BURN UP LONG BEFORE IT WEARS OUT! (hi)
>>
>> UNFORTUNATELY AMERITRON IS HOPELESSLY BEHIND THE POWER CURVE WITH THEIR
>> DEPLOYMENT OF THIS RELAY!
>>
>> I would remind people at this point to keep in mind that there are 3 VERY
>> different kinds of relays used for T/R switching in the linear amplifiers
>> that we use.  The differences are HUGE!
>> You'll find pictures and short description of these on my web site,
>> Here: http://www.dj0ip.de/ten-tec-stuff/misc-stuff/linear-amp-relays/
>>
>> ALTHOUGH AMERITRON publishes a switching time of 15mS for its relays and
>> [falsely] advertises them as "fast- nearly as fast as some QSK relays"
>> [puke], these relays are DIRT SLOW.
>> In reality they switch with 17 to 20mS delay, depending on the situation.
>> *** AS MEASURED LAST WEEK BY BOB, K4TAX. ***
>>
>> Phil is absolutely right!
>> (sorry Gary)
>>
>> NEVER-THE-LESS, there is still a way to have near QSK with the slow
>> Ameritron Amps (without the expensive QSK-5) and still hear in between
>> words; just not in between dit, dahs, or characters.  It's just a matter of
>> proper time sequencing.  I've been doing it with these amps for 30+ years.
>> As long as you can hear between words, there is no tangible disadvantage
>> between QSK that can hear between dits.  OK, perhaps you notice someone is
>> transmitting when you are...  1/10 second later than with true full QSK.  If
>> you are willing to accept this, you can avoid burning the relay.
>>
>> In order to do this, you will need an external keyer that has adjustable
>> time sequencing.  There are a few of these on the market (i.e., WINKEY,
>> MFJ-495, etc.) AND several rig interface boxes such as the "MicroHam
>> MicroKeyer II" have adjustable delay (time sequencing) parameters.  If you
>> understand the timing, it's a piece of cake to set this up.  With devices
>> like that, you may use any keyer - EXCEPT the rig's own built-in keyer.
>>
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt am Main)
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of GARY HUBER
>> Sent: Monday, March 17, 2014 4:40 PM
>> To: TenTec Reflector
>> Subject: [TenTec] QSK or not?
>>
>> 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    -...-.-
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