[Elecraft] xmit and receive frequencies different
Hi gang, My K2 (2631) with KSB2 doesn't transmit and receive on the same frequency. There's about a 70Hz difference on lower sideband and 50Hz on upper. The transmit frequency is always lower than the receive frequency. Carrier supression is great, transmit audio sounds good, and I'm within no more than 100Hz away from the suggested frequencies. The package came with 3.6Khz markings. I've run Cal PLL a number of times. The VFO is accurate and linear. It just won't transmit and receive on the same frequency. Any thoughts? Merlin, W3ICT [EMAIL PROTECTED] ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] my K2 and its different frequencies.
Many thanks to all who answered, including those who helpfully suggested that I might be using RIT or XIT without knowing it. I just put a frequency counter on the BFO on my K2, and it changes about 70Hz when it goes from receive to transmit. Yeah, I know, there's not supposed to be any change, but I get a 70Hz CHANGE IN FREQUENCY BETWEEN RECEIVE AND TRANSMIT. Freq. counter is loosely coupled to the BFO. Any ideas? Merlin, W3ICT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] building versus buying
Interestingly enough, in the late seventies we were complaining about the lack of suitable outlets for homebrew projects. I didn't dcompletely buy it then nor do I buy it now. It's always required ordering out for stuff like ferrites, power transistors, and the like. It's not so bad, you just sit down and order and, voila!, in a few days you're in business. As far as the boards are concerned, there was a great project QST some years ago ago A competition grade CW receiver, in which Doug De Mauw described using a dremel tool, or some such device to make little islands in which to solder the leads of the components. It worked beautifully, giving the builder the benefit of a great, useable groundplane surface area as well. Never having been entirely happy with QRP, in 1980 I built a homebrew, five band rig with a 9 MHZ single conversion design, using an Heathkit LMO as the VFO. It used the then new MRF 422's, and put out 200 very clean watts. I still use this rig with continuing pleasure, enjoying its dual time constant hang AGC and 24 poles of IF filtering (twelve in the receiver and twelve in the transmitter). It used the McCoy Golden Guardian 6 pole filters, one ahead of the IF strip and one after. Because manufacturing cost was not an issue, it was not necessary to bother with bi-lateral circuits or other such shortcuts. The point was, it worked beautifully, and was always a source of pride for me when hams who worked at the Naval Research Labs would come by to see the homebrew project of the ham who lived nearby on Bolling Air Force Base. The other, perhaps best, aspect of this was that, whenever a new design would show up for a mixer or something, in a few hours with the dremel tool and a soldering iron it would reside in the rig. Talk about high tech! I've never been an engineer or techno-geek kind of guy (recently reitired as concertmaster of the Marine Band), but such projects have never been out reach for hams who use even a tiny bit of ingenuity. Homebrew does not have to be dead, even now. Order your doubly balanced mixers, power devices and such, rely on a well-stocked Radio Shack and go for it. Regards, and thanks for this beautiful hobby, Merlin, W3ICT I think we build because of the adventure of it. I can't afford a 8-second drag race car, and my reflexes are a bit slow for Grand Prix Formula One. So?-I build my rig, whether it's a K2 or my own, and I ride a bike, either with a motor or not. That's almost enough excitement. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] Help! my AGC is taking over my K2!
Hi gang, It's Merlin, W3ICT; you know, the guy who complains about the filter in the KSB2 all the time. This time, it's actually something different. Recently I had to replace the finals in my K2 (2631). In the process of measuring forward bias, I accidentally lunched the SC1969s with clumsy metering skills. Got the finals put back no problem, but a strange thing has surfaced, and I wonder if anybody has seen it before. Unrelated to the finals, I turned the K2 on and the S meter pegged and the receiver shut down its 1350P IF amp. I measured the AGC voltage. It's way up there at 5.5 volts, regardless of whether the AGC is disabled and regardless of the position of the RF gain control. Sure enough, if I lift the collector on Q12, the receiver comes up to full sensitivity. If I lift d2 (these are all components on the control board, by the way), thus depriving the AGC amp of a signal from the IF, it still makes no difference; the AGC amplifier still makes too much voltage. Any thoughts? Everything else works, by the way. Does U2 just go bad sometimes? By the way, in the matter of filters, I've come up with a simple shielding technique, using tin sheet from hobby shops, that actually improves the ultimate rejection and the shape factor of the seven pole device that's used in the KSB2. I bet somebody out there has experienced this weirdness. I hope Regards, Merlin, W3ICT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] my final word on tight skirts
I'm pleased that the KDSP2 addresses the issues that limit the KSSB2's performance. And yes, that is a common approach these days; have an unspectacular filter close to the antenna, and clean things up at audio with DSP. This leads me to say two things: We all know, or at least we should know, that the best approach has always been and continues to be, putting the best selectivity as close to the antenna as possible. If the KDSP2 is designed to improve (read, make tolerable) the SSB performance of the K2, the advertising should indicate that the K2 should not be used for serious SSB pursuits unless it's combined with the KDSP2. That would be fair. I'll probably order one (KDSP2) today. I hope Eric realizes that these criticisms come only because the K2 is a history making radio in most other respects. 73, Merlin, W3ICT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] (no subject)
A few days ago somebody was asking who it might be who's been experimenting with shielding on the KSB2 board. I was that guy I suspect, because nobody else I've observed on this net seems to be as annoyed as I about the bad skirts, high ripple, bad ultimate selectivity, etc. when the K2 is used with the KSB2. This is an unbelievably competent radio; no matter whether it's measured against $10,000 machines, $600.00 machines, or whatever. BUT The performance of its filter, and the way that it performs when installed in the radio, is DISMAL On sideband, tight skirts (the electronic kind, gentlemen!) are terribly important, maybe more so than on CW. There is nothing neater than listening to a weak SSB signal through an IF system that has a 1.2:1 shape factor. That complete absence of interference on the sides is marvelous to hear. I'd be surprised if the KSB2 manages 2:1. Just tune through loud broadcast signals on forty meters sometime; listen to the audio images the other side of zero beat even on moderately strong signals. If this radio were a piece of junk that might be acceptable. On a radio that is truly world class in every other respect it's absolutely unacceptable. Take a look at something like a TR-4C; the way the sideband switch is oriented so that the input side of the filters cannot see the output is typical of the care that used to be taken with filter installation. Similar with Collins S line receivers: those not so wonderful mechanical filters are, nevertheless mounted in such a way as to utilize every drop of filtering that's available. That was fifty or so years ago! How far have we come? I have had good success on the KSB2 with shielding the input and output toroids in little tine cans. Yeah, I know, toroids are self shielding; but even the small wires that go into the board act as little antennas. I've also tried putting a small shield on the bottom of the board, separating the input from the output. It works, as well. All of these things work, but I'm more than a little disappointed that apparently no concern was given to filter isolation when the design was originally created. How about somebody designing a filter? I've contacted Inrad; they already have a CW filter for the K2, but the K2's CW performance isn't as much of a problem as it's sideband performance. Inrad doesn't just doesn't seem to be interested in coming up with a sideband filter. Is anybody else as annoyed as I am about this stuff? Merlin W3ICT ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] loops
I love loops. They're quiet, have lots of capture area, wide bandwidth, and when big enough, don't have the big horizontal spikes that collinears or other horizontal wire antennas have. But here's my question: Does anybody know whether the stup on Radio Works's superloop is open or closed? Methinks it's probably open, but I bet somebody out there knows for sure. Merlin, W3ICT, proud owner of K2100 2631 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
