[TenTec] QSK or not?

Mon Mar 17 16:19:57 EDT 2014

Kim, apparently you have never operated a multi-multi station with 6
stations running 1.5kW at the same time, within a few hundred yards of each
other.
And you must not have had Pin Diode switching in Germany because the RF
power in the air at night is significant.
It slightly forward biases the diodes and they cause intermodulation
distortion.

73 - Rick, DJ0IP
(Nr. Frankfurt am Main)

-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Kim Elmore
Sent: Monday, March 17, 2014 8:09 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] QSK or not?

I was thinking more along lines for amplifier switching. I have PIN diode
switches in both of my amps. There are a few AM BC stations within a few
miles of me - one is a 50 kW blowtorch and the others are 1 to 5 kW. I've
never heard any overload problems attributable to the PIN diode switches.
There's only one ham nearby (about 2.5 mi away) who can run 1.5 kW and I've
never heard anything attributable to the switches then, either. The "on"
bias for the rx diodes runs about 100 mA or so and the source voltage is 12
V. 

I can't claim that they can't generate problems (kW field day ops might well
create some as might big multi-multi stations) but I can claim that I've
never encountered any. 

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 13:51, Carl Moreschi <n4py3 at earthlink.net> wrote:
> 
> 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    -...-.-
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>> 
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec at contesting.com
http://lists.contesting.com/mailman/listinfo/tentec