K2 #4293 KAT2, KNB2 etc.
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K2 #4293 KAT2, KNB2 etc.
 
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Hi!
Last weekend I completed KAT2 and KNB2 installation. KNB2 seem to work, but not yet detected any pulse noise on the bands. Regarding KAT2 alignment. 5 W doesn't move needle too much on my Daiwa SWR/power meter, so I can't get accurate power reading for R1 adjustment. I have borrowed Heathkit Cantenna dummy load from our club. There is DC voltage available from this, but I don't have any idea how to convert it to Watts. I have looked in the internet for manual, but only found them for sale. BTW, cantenna resistor is 47 ohms measured with DMM. Should I make small dummy load from resistors similar to DL1 from Elecraft? I ordered XG1 instead of DL1. Maybe I should have read option manuals more carefully to know that I will need it too :( I did MDS measurements last night with XG1. There is small difference between ANT1 and ANT2 connectors of KAT2. ANT1 is -137 dB and ANT2 -135,7 dB. Is there some fault or is it normal? Anyway, I have made several QSOs during weekend. K2 drives my Commander amp to about 500-600 watts and it really helps in pile-ups, YI and 9M2 @ 15m. With 5 watts I got KL7 @ 20m and 4X @ 15m. I need to repair my antenna rotator, beam was pointing towards north all the time. Made also many QSOs from apartment with random wire antenna at 5-10 watts. Including couple of UA9s (closest DX fm hr) on 40 meters. 73 de Jukka, OH4MFA K2 #4293 _______________________________________________________________________ Parhaat hakupalvelut yhdessä osoitteessa: http://www.eniro.fi/ Suomalaisten yritysten tuotteet ja palvelut: http://yritykset.eniro.fi/ _______________________________________________ Elecraft mailing list Post to: [hidden email] http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com |
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Jukka,
Why not just use the RF probe built from the parts supplied with the K2 kit and you will have an instrument that you can trust? The RF probe built into the Heath cantenna MAY be the same thing, but I just can't recall how it is configured. Then you can use the RF probe (and your DMM) connected across the dummy load to measure the rms RF voltage and determine the power output = V*V/R. (The DMM should read the rms value of the RF voltage directly for voltages above about 1 volt) Of course, you must know the resistance of the dummy load accurately too if you are expecting to do an accurate calibration. For a dummy load to be a true dummy load, it must be entirely resistive (no reactance) at the frequency it is being driven. The old Heath cantenna is only OK in this respect, and I have heard reports that the resistance does change a bit with age. (You can check a dummy load by measuring it with an antenna analyzer.) 73, Don W3FPR Life is what happens when you are making other plans ----- Original Message ----- From: "Jukka Tarvainen (OH4MFA)" <[hidden email]> To: <[hidden email]> Sent: Monday, June 21, 2004 5:25 AM Subject: [Elecraft] K2 #4293 KAT2, KNB2 etc. Hi! Last weekend I completed KAT2 and KNB2 installation. KNB2 seem to work, but not yet detected any pulse noise on the bands. Regarding KAT2 alignment. 5 W doesn't move needle too much on my Daiwa SWR/power meter, so I can't get accurate power reading for R1 adjustment. I have borrowed Heathkit Cantenna dummy load from our club. There is DC voltage available from this, but I don't have any idea how to convert it to Watts. I have looked in the internet for manual, but only found them for sale. BTW, cantenna resistor is 47 ohms measured with DMM. Should I make small dummy load from resistors similar to DL1 from Elecraft? I ordered XG1 instead of DL1. Maybe I should have read option manuals more carefully to know that I will need it too :( I did MDS measurements last night with XG1. There is small difference between ANT1 and ANT2 connectors of KAT2. ANT1 is -137 dB and ANT2 -135,7 dB. Is there some fault or is it normal? Anyway, I have made several QSOs during weekend. K2 drives my Commander amp to about 500-600 watts and it really helps in pile-ups, YI and 9M2 @ 15m. With 5 watts I got KL7 @ 20m and 4X @ 15m. I need to repair my antenna rotator, beam was pointing towards north all the time. Made also many QSOs from apartment with random wire antenna at 5-10 watts. Including couple of UA9s (closest DX fm hr) on 40 meters. 73 de Jukka, OH4MFA K2 #4293 _______________________________________________________________________ Parhaat hakupalvelut yhdessä osoitteessa: http://www.eniro.fi/ Suomalaisten yritysten tuotteet ja palvelut: http://yritykset.eniro.fi/ _______________________________________________ Elecraft mailing list Post to: [hidden email] http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com |
Re: K2 #4293 KAT2, KNB2 etc.
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Thank You Don!
I did R1 adjustment during lunchbreak using RF-probe and got it about right. I will check cantenna resistance afterwards and re-adjust if necessary. I was worried about breaking RF-probe, but now I believe I can connect it with dummy load and can't connect it directly to antenna jack. 73 Jukka, OH4MFA K2 #4293 >--Alkuperäinen viesti-- >Reply-To: "Don Wilhelm" <[hidden email]> >From: "Don Wilhelm" <[hidden email]> >To: "Jukka Tarvainen (OH4MFA)" <[hidden email]>, > <[hidden email]> >Subject: Re: [Elecraft] K2 #4293 KAT2, KNB2 etc. >Date: Mon, 21 Jun 2004 09:16:36 -0400 > > >Jukka, > >Why not just use the RF probe built from the parts supplied with the K2 >and you will have an instrument that you can trust? The RF probe built into >the Heath cantenna MAY be the same thing, but I just can't recall how it >is >configured. > >Then you can use the RF probe (and your DMM) connected across the dummy load >to measure the rms RF voltage and determine the power output = V*V/R. (The >DMM should read the rms value of the RF voltage directly for voltages above >about 1 volt) > >Of course, you must know the resistance of the dummy load accurately too >if >you are expecting to do an accurate calibration. For a dummy load to be >a >true dummy load, it must be entirely resistive (no reactance) at the >frequency it is being driven. The old Heath cantenna is only OK in this >respect, and I have heard reports that the resistance does change a bit >age. (You can check a dummy load by measuring it with an antenna analyzer.) > >73, >Don W3FPR > _______________________________________________________________________ Parhaat hakupalvelut yhdessä osoitteessa: http://www.eniro.fi/ Suomalaisten yritysten tuotteet ja palvelut: http://yritykset.eniro.fi/ _______________________________________________ Elecraft mailing list Post to: [hidden email] http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com |
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The peak reverse voltage rating of the diode is the limiting factor for the
RF probe. A 1N34 diode should be fine for power measurements of up to 25 watts across a 50 ohm resistive load - it will make little difference whether connected to the antenna jack or the dummy load. For higher power levels, a higer rated diode could be used or 1N34 diodes could be used in series - the low voltage readings will be more inaccurate if that is done. A coax TEE adapter is one easy way to connect the RF probe to the coax center conductor. 73, Don W3FPR Life is what happens when you are making other plans ----- Original Message ----- I did R1 adjustment during lunchbreak using RF-probe and got it about right. I will check cantenna resistance afterwards and re-adjust if necessary. I was worried about breaking RF-probe, but now I believe I can connect it with dummy load and can't connect it directly to antenna jack. _______________________________________________ Elecraft mailing list Post to: [hidden email] http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com |
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