KX1 10 AND 15 METER MODULE(S)
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Hello all,
Considering the purchase of a KX1. With the sunspot cycle soon to be on the upswing, I'm wondering if Elecraft has any plans to offer 10 and 15 meter options for the KX1. This would certainly add to the versatility of the KX1. 73's Ken, W2GIW K1, K2 _______________________________________________ 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: KX1 10 AND 15 METER MODULE(S)
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Ken asked:
>With the sunspot cycle soon to be on the upswing, I'm >wondering if Elecraft has any plans to offer 10 and 15 >meter options for the KX1. The AD9834 DDS chip in the KX1 is clocked at its maximum rate of 50 MHz. The highest relatively clean frequency that can be generated from a DDS is about one-third of its clock rate (about 16 MHz). Thus, the KX1 design can NOT be adapted to cover ham bands above 20 meters. The coverage of 15m is one of the big advantages of the K1 (which uses a LC VFO and heterodyne oscillators rather than a DDS) over the KX1. 73, Mike / KK5F _______________________________________________ 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: KX1 10 AND 15 METER MODULE(S)
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Mike KK5F wrote:
> The AD9834 DDS chip in the KX1 is clocked at its maximum rate of 50 MHz. > The highest relatively clean frequency that can be generated from a DDS is > about one-third of its clock rate (about 16 MHz). Thus, the KX1 design > can NOT be adapted to cover ham bands above 20 meters. ----------------------------------------------------------------------------------------------- I wonder if it would be possible / practical to replace the KX1's AD9834 DDS chip with another type such as the AD9951 which can be clocked up to 400+ MHz, perhaps lack of space could be a problem. 73, Geoff GM4ESD _______________________________________________ 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: KX1 10 AND 15 METER MODULE(S)
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Geoff,
I believe that might be possible if the package size and pinout are the same as the AD9834, but the firmware would have to change too. If it were not for the firmware problem, adventuresome souls would be able to experiment a bit with it. 73, Don W3FPR > -----Original Message----- > I wonder if it would be possible / practical to replace the KX1's > AD9834 DDS > chip with another type such as the AD9951 which can be clocked up to 400+ > MHz, perhaps lack of space could be a problem. > > 73, > Geoff > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.24/668 - Release Date: 2/4/2007 1:30 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: KX1 10 AND 15 METER MODULE(S)
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Don,
I think that for use in a kit it would probably have to be supplied as part of a factory assembled 'module' if the KX1's firmware could be changed. It is packaged in a Thin Plastic Quad (SV-48) with 48 legs / leads which require careful soldering and the chip needs some form of heat sink. The use of a low noise external oscillator rather than the chip's internal oscillator as the clock source results in lower and useful levels of close in phase noise at the chip's output, but of course adds complexity. 73, Geoff GM4ESD ----- Original Message ----- Geoff, I believe that might be possible if the package size and pinout are the same as the AD9834, but the firmware would have to change too. If it were not for the firmware problem, adventuresome souls would be able to experiment a bit with it. 73, Don W3FPR _______________________________________________ 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: KX1 10 AND 15 METER MODULE(S)
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In reply to this post by Geoffrey Mackenzie-Kennedy-2
Actually, the 9834 is now spec'ed to 75MHz. Problem is
finding oscillators. It happens to be the very same DDS in the KD1JV ATS radios and a few folks have already swapped DDS chips, changed the oscillator, modified the DDS filter, changed the firmware and put their rigs on higher bands--12M being the highest due to Nyquist considerations. So yes it could be done, but you would have to write new firmware for the KX1 and somehow grow some more space for the extra filters and relays that are gonna be neccessary. I don't see it as being practical. -mike/w1mt --- Geoffrey Mackenzie-Kennedy <[hidden email]> wrote: > Mike KK5F wrote: > > > The AD9834 DDS chip in the KX1 is clocked at its > maximum rate of 50 MHz. > > The highest relatively clean frequency that can be > generated from a DDS is > > about one-third of its clock rate (about 16 MHz). > Thus, the KX1 design > > can NOT be adapted to cover ham bands above 20 > meters. > > > > I wonder if it would be possible / practical to > replace the KX1's AD9834 DDS > chip with another type such as the AD9951 which can > be clocked up to 400+ > MHz, perhaps lack of space could be a problem. > > 73, > Geoff > GM4ESD > > ____________________________________________________________________________________ Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 _______________________________________________ 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: KX1 10 AND 15 METER MODULE(S)
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In reply to this post by KEN-101
Mike wrote:
>Actually, the 9834 is now spec'ed to 75MHz. I believe that's only since mid-2006. Most of the installed base of AD9834 chips would be 50 MHz rated. >Problem is finding oscillators. That's seems to be very true if one searches on-line catalogs. The one for the KX1 comes pre-installed on the PCB. >a few folks have...put their rigs on higher bands--12M being >the highest due to Nyquist considerations. It makes one wish for a "KX2" that was designed to provide up to at least 17m and 15m coverage. Those are excellent QRP bands when open. I'd also like to see a four-pole IF filter in the receiver, and a little more wide-range for the internal antenna tuner. That rig might actually compete with the K1 for my QRP rig affections. >So yes it could be done, but you would have to write >new firmware for the KX1 and somehow grow some more >space for the extra filters and relays that are gonna >be neccessary. I don't see it as being practical. Not at all practical. That's why a non-trivial alteration of the KX1 design would be required, enough to warrant a new model number, I think. 73, Mike / KK5F _______________________________________________ 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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