Carl is right.
That was our second reason for going away from PIN-Diodes.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Carl
Moreschi
Sent: Monday, March 17, 2014 7:51 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] QSK or not?
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@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@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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