K2 #5549 some questions/remarks
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Hi,
First of all Merry Christmas to all of you! Yesterday I went over to a friend and we did some quick tests on my new K2 (basic, no options yet). To be clear, everything has been aligned with basic tools, as in the user manual. Here are some things we noticed: 1. when looking at the transmitted signal using a spectrum analyser, the signal didn't seem as clean as we liked it. We didn't have time (it was the day before X-mas!) to really start counting the dB's, but on 30, 12 and 10 m we saw some signals around the main signal. Is there any chance we can get these bands 'cleaner' by further tweaking the filters? 2. Output power on 10m is OK low in the band, but when going higher up it decreases to a mere 1,5 W. Moreover the higher we go in the band the worse the transmitted spectrum gets (see above). Is it possible to set the filters so the complete 10m band can be used at a reasonable power? I know, for CW the low part of the band is the place to be, but I'd like to also install the SSB option. 3. When listening to a continuous signal (XG2 for example) there is some kind of a (digital) 'thump' in the audio everytime I turn RIT or VFO. Is this a normal behaviour or not? -- 73 Jurgen Geldhof ON5MF [hidden email] <mailto:[hidden email]> ------------------------------------------------------------------------ my site: www.on5mf.be <http://www.ktk.be> our club: www.ktk.be <http://www.ktk.be> the Belgian Amateur Radio Society: www.uba.be <http://www.uba.be> ------------------------------------------------------------------------ _______________________________________________ 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 |
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In a message dated 25/12/06 10:53:49 GMT Standard Time, [hidden email] writes: 1. when looking at the transmitted signal using a spectrum analyser, the signal didn't seem as clean as we liked it. We didn't have time (it was the day before X-mas!) to really start counting the dB's, but on 30, 12 and 10 m we saw some signals around the main signal. Is there any chance we can get these bands 'cleaner' by further tweaking the filters? ----------------------------------------------------------------- Hi Jurgen, Are you 100% sure that the spurii you are seeing are just not due to you overloading the input of the spectrum analyser? This is a common cause of apparent excessive spurii! Merry Christmas to all, Bob, G3VVT _______________________________________________ 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: K2 #5549 some questions/remarks
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In reply to this post by Jurgen ON5MF
Jurgen,
If you peak the 10 meter bandpass filter at 28.4 MHz, you will have greater power output at 28.8 MHz. Note that the specified 10 meter band coverage for the K2 is 28.0 to 28.8 MHz. Above that range, the output power is expected to decrease. There are mods to increase the 10 meter bandpass filter width if you should choose to do that. See http://www.qslnet.de/member/la3za/K2/mod.html for more information. 73, Don W3FPR > -----Original Message----- > 2. Output power on 10m is OK low in the band, but when going higher > up it decreases to a mere 1,5 W. Moreover the higher we go in the > band the worse the transmitted spectrum gets (see above). Is it > possible to set the filters so the complete 10m band can be used > at a reasonable power? I know, for CW the low part of the band is > the place to be, but I'd like to also install the SSB option. -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.26/601 - Release Date: 12/24/2006 11:31 AM _______________________________________________ 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: K2 #5549 some questions/remarks
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In reply to this post by Jurgen ON5MF
Hi, Jurgen:
Regarding 10 meters, the specifications say the K2 will deliver at least 10 watts from 28.0 to 28.8 MHz - a range of 800 kHz. It is not designed to cover the whole 10 meter band. I'm not sure where you see the power drop off, but if it's making 10 watts at 28.8 MHz it's working within spec. Ron AC7AC -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Jurgen ON5MF Sent: Sunday, December 24, 2006 11:43 PM To: [hidden email] Subject: [Elecraft] K2 #5549 some questions/remarks Hi, First of all Merry Christmas to all of you! Yesterday I went over to a friend and we did some quick tests on my new K2 (basic, no options yet). To be clear, everything has been aligned with basic tools, as in the user manual. Here are some things we noticed: 1. when looking at the transmitted signal using a spectrum analyser, the signal didn't seem as clean as we liked it. We didn't have time (it was the day before X-mas!) to really start counting the dB's, but on 30, 12 and 10 m we saw some signals around the main signal. Is there any chance we can get these bands 'cleaner' by further tweaking the filters? 2. Output power on 10m is OK low in the band, but when going higher up it decreases to a mere 1,5 W. Moreover the higher we go in the band the worse the transmitted spectrum gets (see above). Is it possible to set the filters so the complete 10m band can be used at a reasonable power? I know, for CW the low part of the band is the place to be, but I'd like to also install the SSB option. 3. When listening to a continuous signal (XG2 for example) there is some kind of a (digital) 'thump' in the audio everytime I turn RIT or VFO. Is this a normal behaviour or not? -- 73 Jurgen Geldhof ON5MF [hidden email] <mailto:[hidden email]> ------------------------------------------------------------------------ my site: www.on5mf.be <http://www.ktk.be> our club: www.ktk.be <http://www.ktk.be> the Belgian Amateur Radio Society: www.uba.be <http://www.uba.be> ------------------------------------------------------------------------ _______________________________________________ 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 _______________________________________________ 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: K2 #5549 some questions/remarks
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In reply to this post by Jurgen ON5MF
A few months ago, after completing #5390, I ran a check on the cleanliness of the K2 transmitted CW signal on 28Mhz, using the spectrum scope in my IC-781 as a spectrum analyser. I could not detect any trace of spurii and the slopes of the received trace were sharp and smooth, with the scope set to 5Khz per division. Signal also sounded clean and pure to listen to.
I had to set up a high degree of 'attenuation' between the K2/dummy load and the IC-781 (with a wire antenna about 1 ft long), which I did by having the K2 running dits into the dummy load in one room of our apartment, and the IC-781 in another room some distance away. If you try this, take care to arrange enough proper attenuation, to avoid the risk of blowing the RF stage or switching diodes in your RX! 73 and Happy Holidays to all, Wyn, VR2AX In a message dated 25/12/06 10:53:49 GMT Standard Time, [hidden email] writes: 1. when looking at the transmitted signal using a spectrum analyser, the signal didn't seem as clean as we liked it. We didn't have time (it was the day before X-mas!) to really start counting the dB's, but on 30, 12 and 10 m we saw some signals around the main signal. Is there any chance we can get these bands 'cleaner' by further tweaking the filters? ----------------------------------------------------------------- Hi Jurgen, Are you 100% sure that the spurii you are seeing are just not due to you overloading the input of the spectrum analyser? This is a common cause of apparent excessive spurii! Merry Christmas to all, Bob, G3VVT _______________________________________________ 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: K2 #5549 some questions/remarks
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In reply to this post by G3VVT
Hi everyone,
thanks for the replies so far. No the spurious we see are not due to overloading of the spectrum analyser. They are really there! We saw them on 30, 12 and 10m, the other bands were a lot 'cleaner'. We (ON7KZ and I) have no time to get into it in the first few days but the file http://www.qslnet.de/member/la3za/K2/BpfDL7MAJ.pdf seems pretty helpful. More info to follow here or on my homepage. Any hints or tips are still welcome! [hidden email] wrote: > In a message dated 25/12/06 10:53:49 GMT Standard Time, > [hidden email] writes: > > 1. when looking at the transmitted signal using a spectrum analyser, > the signal didn't seem as clean as we liked it. We didn't have > time (it was the day before X-mas!) to really start counting the > dB's, but on 30, 12 and 10 m we saw some signals around the main > signal. Is there any chance we can get these bands 'cleaner' by > further tweaking the filters? > > ----------------------------------------------------------------- > > Hi Jurgen, > > Are you 100% sure that the spurii you are seeing are just not due to > you overloading the input of the spectrum analyser? > > This is a common cause of apparent excessive spurii! > > Merry Christmas to all, > > Bob, G3VVT -- 73 Jurgen Geldhof ON5MF [hidden email] <mailto:[hidden email]> ------------------------------------------------------------------------ my site: www.on5mf.be <http://www.ktk.be> our club: www.ktk.be <http://www.ktk.be> the Belgian Amateur Radio Society: www.uba.be <http://www.uba.be> ------------------------------------------------------------------------ _______________________________________________ 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 |
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