Re: [Elecraft] OT: How do you measure common mode current?
Steve, VK2SJA wrote: I've done some web surfing re this issue and it appears that for EMI testing they use a wide band RF pickup of some sort and a sprectrum analyzer. Given that I don't have a spectrum analyzer and that I'm not concerned with laboratory accuracy is there a simple way of finding out the level of common mode current floating on your coax? Yes, there is a simple device that is very easy to build which will detect common mode current on the outside of coax, and can be thought of as a 'current transformer' plus detector driving a meter. Without calibration, which would require other test equipment, the device will let you know if there is common mode current flowing and whether it decreases or increases after making a change. Other versions are useful for detecting RF current in things such as above ground telephone cables which could be affecting an antenna's performance. Please let me know off- list if you are interested in seeing details. 73, Geoff GM4ESD ___ 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] Re: OT: How do you measure common mode current?
Hi Steve, Question: How do you go about detecting common mode current on the outside braid of your co-axial cable and then measuring or quantifying the amount thereof? You need a shield current meter. They're easy enough to build: http://w8ji.com/building_a_current_meter.htm And cheap enough to buy: http://www.mfjenterprises.com/products.php?prodid=MFJ-853 http://www.mfjenterprises.com/products.php?prodid=MFJ-854 I have an MFJ-853 that works as advertised, and it's a usefull device. Standard disclaimer applies.. 73, Ken Rice K3VV Coopersburg, PA ___ 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
Re: [Elecraft] Noise Blanker
I'm arriving at this conversation a bit late, but let me ask this question. I have a relatively newly assembled K-2, working perfectly as far as I can tell. I have the KNB2 assembled and ready to install. After reading these posts, I'm wondering if I should bother to do it. I find, as Ron said, the filters do a good job with atmospheric noise. I don't have anything else unusual here in the way of noise. Sometimes I get line noise, but it's so irritating I usually don't try to work through it. I'll wait it out. So, should I risk the uninstalling of resistors and cutting of jumpers on a good radio for the improvement offered by the noise blanker? Jimmy Walker WA4ILO Macon, GA - Original Message - From: ron [EMAIL PROTECTED] To: elecraft@mailman.qth.net Sent: Wednesday, September 27, 2006 5:50 PM Subject: Re: [Elecraft] Noise Blanker Hello all; I push on a CW filter and it does the same thing! I also press attenuate with same results! Unh? Noise blanker and/or filter does same thing? Why? Because filters and NB may appear to remove atmospheric noise, but it's still there, because it's attenuated. (There's a little more to that but not here) Noise blankers work more effectively on man-made noise such as automobiles, lights, motors, hair dryers (pulse type noise) etc. Not atmospheric noises. Oh, after you did that, you probably had to turn up the volume a bit like I did. It make for easier listening though. Regardless, I love me K1. (smile) Ron, wb1hga W.D. (Doc) Lindsey wrote: evening here on 30Metres, and the QRN seemed incessant, I [probably] accidentally pushed the NB button on a K2. And suddenly the noise all but disappeared. Since then I have come to use it regularly, as there seems to be a whole lot of QRN here in the tiny subdivision. But the NB will normally knock it down to listenable levels. ___ 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 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] Clamp on RF meter
Steve, This might help you find out if RF is flowing on your coax sheild, someone on the reflector (it eludes me at the moment who...) has a similiar device he homebrewed. http://www.ifwtech.co.uk/g3sek/clip-on/clip-on.htm You might take a look at the W8JI site (www.w8ji.com) for some thoughts on the topic. I know it was pretty evident on 160 for me, with 100W and RX noise. A current choke and/or isolation transformer close to the antenna and before entering the house will virtually eliminate common mode problems. LB Cebik W4RNL gave a presentation on the subject at a recent ETDXA meeting see: http://www.cebik.com/trans/cmp.html 73, Julius n2wn ___ 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] The ongoing construction of K2 #4455
It's almost there, final tests this week, maybe on the air by the weekend. Thanks to the folks at Elecraft, Don and Tom for assists during the spotty construction. It's tough when you can't just sit down and just build... Tom, N0SS, Cheap and Dirty signal tracing was a great help when I had a dead Rx (seems I neglected to install C6 and missed seeing it wasn't installed several times). This reflector, and the people who populate it, is a tremendous resource. 73, Julius n2wn ___ 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
Re: [Elecraft] Icom 735 inquiry
With my last IC-735, I recall I did inquire to ICOM AMERICA, State of Washington, about their replacing the RAM MEMORY BATTERY in my IC-735. If I'm not mistaken, they said they no longer carry it. But there are several outfits who sell memory backup products, for the IC-735. I forget now, but Icom's Service Dept. did tell me what they could and could not fix on a IC-735. There is also an issue with the IC-735's display capacitors, a replacement need. I think Icom, last year, said they could replace those. I think the brunt of IC-735's were built in the mid to later 80's. So kind of aging a bit now. For the money, a nice little rig, and GC receive too. Fred N3CSY __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ 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
Re: [Elecraft] Noise Blanker
NB removes man-made noise, NOT atmospheric noise. Filters DO NOT remove man made noise. Nor do they remove atmospheric noise. As I wrote, they give the appearance the noise is gone, when turned on to narrow the bandwith. That's why you turn up the volume a bit to compensate. The filter's job is to reduce bandwith. (there's more but not here) There is no risk to install NB's and it's a positive move. It just may rid of that line noise you wrote. You will enjoy your radio more, instead of waiting for that to go away. (smile) Ron, wb1hga Jimmy Walker wrote: I find, as Ron said, the filters do a good job with atmospheric noise. I don't have anything else unusual here in the way of noise. Sometimes I get line noise, but it's so irritating I usually don't try to work through it. I'll wait it out. So, should I risk the uninstalling of resistors and cutting of jumpers on a good radio for the improvement offered by the noise blanker? ___ 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] 40M DX and DSP
I am very impressed with the K2 RCVR and DSP. I didn't really expect much DX on 40M but usually around 11:30 pm (0330 UTC) and around 7005 KHz lots of European stations from Russia, Bulgaria, Ukraine to France, Sweden, Germany. But last night I heard 9J2BO, Brian, in Zambia. No QSO but impressive nonetheless (to me anyway). I have heard some report dissatisfaction with DSP in the K2. Here's what I do. I use wide open bandwidth and no DSP until I find a weak DX station. I tighten up the XFIL and then apply the DSP. (Frankly, I don't usually use the AFIL much ... it seems a bit redundant, even though the AF filtering is different than the XFIL.) I find the DSP usually makes a very large difference in the noise floor and the weak signal is much more discernible. My two cents worth, John AB8O ___ 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
RE: [Elecraft] Icom 735 inquiry
I had an IC735. On paper it sure looked like a great rig. In practice I found the sound of the rig to be irritating. Background noise was harsh and spiky for lack of a better word. Recovered audio left me wanting to turn the rig off. GC receive, which I though would be a great thing, turned out to be something I almost never used. I tried to like it, really. I had wanted one for years but found quickly after owning one that it was not gonna hold my interest. As soon as the K2 was up running, the 735 went up for sale. I'm sure there a lot of happy IC-735 owners out there (notice how I've spelled it 3 different ways in this post? :-) but I'm not one of them. YMMV - Keith KD1E - - K2 5411 - -Original Message- I think the brunt of IC-735's were built in the mid to later 80's. So kind of aging a bit now. For the money, a nice little rig, and GC receive too. ___ 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
Re: [Elecraft] Clamp on RF meter
J F wrote: This might help you find out if RF is flowing on your coax sheild, someone on the reflector (it eludes me at the moment who...) has a similiar device he homebrewed. Here is one I made: http://www.qsl.net/k2vco/sniffer/rfsniffer.html -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco ___ 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
Re: [Elecraft] Common mode current
If you're talking about common mode currents in a low gain receive antenna like a Pennant, K9AY loop, EWE, etc., common mode currents are of great concern because any signal picked up by the coax is very significant compared to the desired signal picked up by the antenna. Common mode currents are of much less concern on a transmit antenna such as a coax-fed dipole or inverted vee, where the received signal (and noise) is much stronger. For the above-mentioned receive antennas, a choke balun is the easiest way to combat common mode currents. It can be made by coiling up the last 38' of coax at the antenna feedpoint into 12 turns, 12 inches in diameter. For transmit antennas, the same method may be used, or a 1:1 balun may be installed at the feedpoint. 73, de Earl, K6SE ___ 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
Re: [Elecraft] Noise Blanker
I is my experience that the K2 Noise Blanker is quite effective on certain types of impulse noise, while of little help on others, i.e., it is quite dependent on the characteristics of the noise. For atmospheric noise, the noise reduction function of the KDSP2 works better than anything else I have tried. I recommend having both. 73 - Bob, N7XY ___ 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
Re: [Elecraft] Clamp on RF meter
Thanks Vic, you're the gent I was thinking of when I wrote this! Cheers, Julius n2wn --- Vic K2VCO [EMAIL PROTECTED] wrote: J F wrote: This might help you find out if RF is flowing on your coax sheild, someone on the reflector (it eludes me at the moment who...) has a similiar device he homebrewed. Here is one I made: http://www.qsl.net/k2vco/sniffer/rfsniffer.html -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco ___ 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
RE: [Elecraft] KPA100 - L15 Inductor
David, Manual Rev D is the latest, and yes, if you look at page 21 and page 41 of the KPA100 manual, you should see that C82, L15 and R12 positions are not populated. You may have a use for that extra core someday, but 8 are sufficient in the KPA100 - you just got an extra one. 73, Don W3FPR -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Tuesday, October 10, 2006 6:46 PM To: elecraft@mailman.qth.net Subject: [Elecraft] KPA100 - L15 Inductor Hi All, Just a quick query!! I'm putting together a KPA100, and want to just confirm that the outline for Inductor L15 on the circuit board should be left empty. I can't find any reference to L15 in the manual (Revision D), but when I've looked at the online manual to search for the part, it is there, but the on-line manual is Revision C. I'm assuming this was changed between Revision C and D ?? I just wanted to confirm this, as I have seem to an extra torroid (T50-10 black core). The manual says I should have 8, but I actually got 9. Thanks David, Vk2NU ___ 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 -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.408 / Virus Database: 268.13.1/470 - Release Date: 10/10/2006 ___ 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] WA3WSJ: Bead-Wire Antenna in the Field
Hello all, I hiked up to Pulpit Rock about a two-mile hike straight up the mountain for the PBMME. After setting up my KX1 and my Bead-Wire Antenna, I called CQ and WA8REI came back to me from MI! He gave me a 579 report and he was strong as well. I worked more stations after him including an IK2 on 30m with 3.5w. Looks like I have a winner to use for backpacking. I'll post some pictures on my website soon. By the way the entire Bead-Wire Antenna weighs-in at 2 oz. including the small spool! That's 40' of bead wire for the radiator and three 16' ground radials! The wire is the type used for beading -yes jewelry! 72, Ed,WA3WSJ ___ 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
RE: [Elecraft] KPA100 - L15 Inductor
You are correct David. You should have checked off a step where you confirm that nothing is installed in the space on the PCB for L15. (See page 21 of the Rev. D manual, left column) Also it's listed again as a part that is not installed on page 41 just before you button up the amp. Wayne left it on the schematic diagram so curious builders could see what it was originally - an inductance in parallel with the secondary of transformer T2, between the power output transistors and the t/r switch circuit - and he added a note saying 'not used' next to it. It's on sheet 1 of the schematic (page 70). Ron AC7AC -Original Message- Hi All, Just a quick query!! I'm putting together a KPA100, and want to just confirm that the outline for Inductor L15 on the circuit board should be left empty. I can't find any reference to L15 in the manual (Revision D), but when I've looked at the online manual to search for the part, it is there, but the on-line manual is Revision C. I'm assuming this was changed between Revision C and D ?? I just wanted to confirm this, as I have seem to an extra torroid (T50-10 black core). The manual says I should have 8, but I actually got 9. Thanks David, Vk2NU ___ 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] N-gen
I built the N-gen and the noise does not increase like it is supposed to. I re-heated the joints, checked for proper part placements but it still doesn't work properly--- until I hold my finger across R1 and R5 at the same time, then the noise increases. Anyone else run into this problem ? And if so what corrected it. Ken K1DWZ ___ 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
