What does SWR-protected mean?
Locked
 
|
I noticed on the Elecraft website, that both the K1 and K2
specifications use the term "SWR-protected" in the description of the PA transistors. What does this mean, exactly? If the K1 or K2 is presented with high SWR, will the radio shut down or shut off or unkey or something? Thanks and 73 de Stephanie va3uxb K2#5311 - K1#2132 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
RE: What does SWR-protected mean?
|
|
Stephanie, VA3UXB wrote:
I noticed on the Elecraft website, that both the K1 and K2 specifications use the term "SWR-protected" in the description of the PA transistors. What does this mean, exactly? If the K1 or K2 is presented with high SWR, will the radio shut down or shut off or unkey or something? -------------------------------------- I just had that experience with my K2/100 last night, Stephanie. I was chatting with a station on 80 meter CW, running 100 watts, when I noticed the power output go to zero. I still had sidetone as I keyed, just no RF output. Now, in six years of operation with K2 S/N1289, I've never seen a burble. Power was still on, but output was zero. I applied "immediate action". In the Army that means kick the $#$@% out of your weapon when it jams in the middle of battle. On the K2 I was a little less violent: I cycled the power off then on again. Keyed the rig and RF output was back and normal. Hmmmm... "red flag".... But it keyed FB and I apologized for the break to the other guy and continued with the QSO. A minute or two later it happened again. Cycled power again. Now I'm wondering if the Astron supply is dying. A minute or so later it happened again. This time I caught a glimpse of "HI REFL..." on the LCD and notice my external SWR meter jump too. So I signed and investigated. I had been swapping cables around and the antenna cable to my external ATU was loose and making intermittent connection. When it would break connection, the SWR went "through the roof" at full power and the 100 watt amp shut down automatically without damage. Tightening the connector fixed the problem. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: What does SWR-protected mean?
|
|
It's usually not that drastic, though. The real meaning is that
transmit power folds back when the K1/2 sees high SWR in order to protect the PA transistors. Power doesn't necessarily go to zero unless a really severe SWR was encountered. I made pretty good use of this in the NAQP contest last evening. Operating 160 meters on my 80/40 trap dipole caused the K2/100 to see just this condition. My output power dropped quite a bit, but I usually made the QSOs (about eight as I recall). They were pretty much all locals, but the points count. The idea here is that we try to engineer the radios to protect themselves in the event of a fault (high SWR is considered a fault), but keep on working. This allows you to finish what you were doing, then correct the fault as soon as you can and quickly return to full operation. In my case correcting the fault involves figuring out how to get a decent 160m antenna on my small city lot. ;-) Now back to work... On Jan 22, 2006, at 10:43 AM, Ron D'Eau Claire wrote: > Stephanie, VA3UXB wrote: > I noticed on the Elecraft website, that both the K1 and K2 > specifications use the term "SWR-protected" in the description of the > PA transistors. > > What does this mean, exactly? If the K1 or K2 is presented with high > SWR, will the radio shut down or shut off or unkey or something? > > -------------------------------------- > > I just had that experience with my K2/100 last night, Stephanie. > > I was chatting with a station on 80 meter CW, running 100 watts, > when I > noticed the power output go to zero. I still had sidetone as I > keyed, just > no RF output. > > Now, in six years of operation with K2 S/N1289, I've never seen a > burble. > Power was still on, but output was zero. I applied "immediate > action". In > the Army that means kick the $#$@% out of your weapon when it jams > in the > middle of battle. On the K2 I was a little less violent: I cycled > the power > off then on again. Keyed the rig and RF output was back and normal. > Hmmmm... > "red flag".... But it keyed FB and I apologized for the break to > the other > guy and continued with the QSO. > > A minute or two later it happened again. Cycled power again. Now I'm > wondering if the Astron supply is dying. > > A minute or so later it happened again. This time I caught a > glimpse of "HI > REFL..." on the LCD and notice my external SWR meter jump too. So I > signed > and investigated. > > I had been swapping cables around and the antenna cable to my > external ATU > was loose and making intermittent connection. When it would break > connection, the SWR went "through the roof" at full power and the > 100 watt > amp shut down automatically without damage. Tightening the > connector fixed > the problem. > > Ron AC7AC > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com - Jack Brindle, W6FB ------------------------------------------------------------------------ --------------------- _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
«
Return to Elecraft
|
1 view|%1 views
| Free forum by Nabble | Edit this page |