Phase noise etc.
Locked
 
|
Hi all.
Seems this ongoing phase noise issue is getting abit stale don't get me wrong I understand that all amateurs strive for the importance of having clean/ noise free transmissions without causing other operators undue interference. Also I understand the importance of a low noise floor for vhf weak signal work as I am a keen 144mhz dxer with low power that is 50w max,so the thread is interesting to me as I am contemplating a XV144 to go side by side with my K2 #4785 to run around 15/20 watts out here in europe. If i remember when I first encountered information regarding the K2 I was reading a QRP magazine and it was claimed the K2 was developed as a high performance QRP tranceiver along with the K1 that I am also the proud owner of. It has been well documented that the K2/K1 works very well in this role (I AGREE) It seems that some operators are having problems with magnetic interferance within the pll circuit & various ways to protect this circuit with sheilding,please take time here to think that most of the top range black box tranceivers that are on the market today probably have more money spent on their sheilding and imunity to strong interferance than the total cost of the K2 plus a few options. Please dont get me wrong as I do not have the test equipment to test for some of the recent issues under the above topic nor do I have the experience to carry out these tests,but i am pretty sure that synth phase noise and the recent change in topic regarding magnetic interferance are slightly different. All the best rant over Hi. Mick M1MGD..72/73 _______________________________________________ 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 |
|
|
Mick, M1MGD wrote:
"...i am pretty sure that synth phase noise and the recent change in topic regarding magnetic interferance are slightly different." ========== It all started when one of the reflectees wrote, "...in many respects the K2 does outperform other rigs, but unfortunately in terms of transmitted phase noise it does not. This is not an issue at low power, for which I think the K2 was originally designed, but becomes noticeable when the K2 is used to drive an external linear." Notice the last part of his statement. That's when I chimed in and said the cause was not "synth phase noise" (which it isn't). I consider the topic has never changed. 73, de Earl, K6SE _______________________________________________ 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 |
|
|
In reply to this post by M1MGD1
Mick, M1MGD wrote:
...please take time here to think that most of the top range black box tranceivers that are on the market today probably have more money spent on their sheilding and imunity to strong interferance than the total cost of the K2 plus a few options. ------------------ I hope they keep at it. Here's why. My K2/100 S/N 1289 is going on five years old now, and the thread on phase noise reminds of several others that went on and on and on and... One was about the lousy reception on SSB one sideband, even with the SSB adapter installed. That led to a discovery that the 2nd XFIL at the i.f. output had a passband tilt that made some bands sound bassy and others with exceptionally bright highs. The 2nd XFIL mod came of that and it became a basic part of the design at S/N 3000. Then there were those ops plagued by noisy audio pots which turned out not to be a problem with the pot at all but the way it was used in the circuit. Long ago that was changed. And almost immediately there was a long discussion about ripple and the bandwidth of the OPT1 filter on the SSB board that at first was written off as a bunch of overly-picky ops until Wayne & Eric discovered that the spex they had on the crystals being sent out with the kits weren't tight enough. Some SSB filters had bandwidths as low as 1.8 kHz - way too "tight" for decent audio no matter how the BFO was adjusted. Those of us whose filters didn't meet specs got, gratis, a whole new set of crystals. Other ops who weren't experiencing problems were offered new crystals if they wanted them at a nominal price. And John Grebenkemper produced some alternate OPT1 filter setups using various mixes of capacitors to provide builders with a selection of filters bandwidths and lower passband ripple! Somewhere along the way someone noticed a "howl" in their K2 when strong signals were present - as in a multi-op field day environment. That also produced a long thread that resulted in the addition of two diodes to the i.f. amplifier to keep it stable no matter how much RF hits it from nearby rigs. I could go on and on with many more such improvements to the K2, almost every one of which seemed some esoteric unsolvable issue affecting only a few ops at first. These are enough, I hope, to make the point that we never know what is involved in making an improvement until someone figures it out. One of the biggest "features" in the K2 - in all of the Elecraft rigs - is Elecraft's support of those who want to dig in and tinker and try improvements. I consider that a huge improvement over the other manufacturers who can only advise ops who notice a deficiency in their rig to dump it at the next Hamfest and trade up to the latest super-mega-whopper box at twice the price because, perhaps, just perhaps, that problem was fixed in the last redesign... I find this subject very interesting, and I hope the ops working the problem keep posting on the reflector for all of us. 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 |
|
|
Great post Ron, this is the reason I have stuck with the Elecraft reflector.
And also why I now own all three elecraft rigs. I have learned so much by reading the discussions even when they do not apply to me or seem important. Doc, YI9RVT/KE4RVT _______________________________________________ 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 |