Re: [Elecraft] K3 RX below 500 kc/s
Hi Jim, I looked into this. A small percentage of K3s would be able to tune below 500 kHz as-is (to 400 or 450 kHz), but most would require a synthesizer board modification. The original design was not intended to go below this level. 73, Wayne N6KR On Mar 31, 2009, at 9:57 PM, Jan Erik Holm wrote: This was on the agenda a while ago. Any progress on it? 73 Jim SM2EKM --- http://www.elecraft.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 RX below 500 kc/s
Might be a good idea for down the road to include 2200 meters (135.7-137.8kc), 1750 meters (160-190kc) 600 meters (495-515kc) as some countries already have those bands as Amateur bands. There are groups in the US working to get all three bands as Amateur Bands. The ARRL is one of them. Frequency stability is extremely important for operating on those LF MF bands. Mike WE0H WD2XGI on 2200 1750m WD2XSH/16 on 600m __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 RX below 500 kc/s
Mike-WE0H wrote: Frequency stability is extremely important for operating on those LF MF bands. Can´t see why it´s more important on LF then on HF/VHF/UHF however frequency stability is always good. Jim SM2EKM __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 - Revolutionary Noise Reduction
Larsen E Rapp would have been so proud! A true technological achievement. Had this idea been advanced sooner, I am sure it would have been equally applicable to his famous QS-59 receiver, itself a technical miracle well beyond it's time! - Jim, KL7CC Tony Fegan VE3QF wrote: K3 - Revolutionary Noise Reduction It was announced today, by Professor Morsig at the Institute of Ljubljana, that the K3 has been chosen to test a revolutionary new approach to combating receiver noise and improving HF reception. The basic principal behind this approach is the shifting in frequency of noise by a few mHz (that's milli-hertz) away from the tuned frequency. This in effect produces a hole in the noise spectrum where weaker signals may be detected. The residual noise is directly proportional to the bandwidth of the hole. Therefore, for wider signals, such as SSB, a modified approach is required. The hole is moved progressively over the required signals bandwidth and the signal is sampled at each step and integrated to reproduce the original wideband signal. A second feature associated with this algorithm deals with variations in propagation. We all know that propagation is largely dependent on the solar flux. Propagation is changed due to the effects of the solar wind. A little known fact is that the remnants of the solar wind that reach the receive antenna modulates the noise. When the noise is detected this modulation can be interpreted to give information about the condition of the D, E and F layers. This can be used to produce a real-time table of MUF and critical frequencies for each layer. At night some kind of remote sensing with suitable location corrections has to be used. The third and more revolutionary feature, which depends heavily on the previous features, involves the generation and use of virtual transceivers or individual ionosphere layer repeaters. As an example we will assume a distant CW signal is transmitted on 21.110Mhz and the MUF is around 15.000Mhz. The signal will not be refracted to our receiving station and most of it is lost in space. If we transmit a heterodyning carrier pulse on 14.110MHz, which is below the MUF, then it will mix with the transmitted signal and produce a weak signal pulse at 7.000MHz which is reflected back to the receiving station. There is a time delay between the sending of the pulse and receiving the return pulse. The transmitted pulse length is made less than this delay so that the 7.000MHz return pulse may be received between transmit pulses. This process is repeated and the received signals integrated to reconstitute the original signal sent. There are some operating problems to be worked out with the transmission of multiple heterodyning carriers. Thus only a few K3's are expected be loaded with the new firmware until these problems are resolved (spread spectrum has been suggested). New menu items may be added to include these features in a future K3 DSP firmware update. MUF OFF/AUTO and 1-10 will vary the effect of received signals using simulated MUF values. This can improve signals on all bands. Unfortunately this enhancement is not reciprocal and only works on receive. Thus K3 to K3 contacts should have a distinct advantage. The algorithms used are not open source as these features are expected to have a huge affect on the whole radio communications industry. It is still in the early beta-test stages. The above is a rough summary of the original unwinese language document submitted by Professor G. E. T. Morsig who is the 1st Associate Professor of Radio at the Institute of Ljubljana. He will be very interested in your assessment of this system and may be contacted via F(zero)OL (qrz.com). My apologies if I have made a minor slip or two in the translation. Unwinese is not an easy language to translate. Please do not contact Elecraft for this firmware until there is an official statement! 73 and Enjoy Tony Fegan VE3QF (anxiously awaiting further developments!) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 - Revolutionary Noise Reduction
At some point we are all April fools! Good one! Mike, ks7d On Apr 1, 2009, at 12:01 AM, Tony Fegan VE3QF jafe...@rogers.com wrote: K3 - Revolutionary Noise Reduction It was announced today, by Professor Morsig at the Institute of Ljubljana, that the K3 has been chosen to test a revolutionary new approach to combating receiver noise and improving HF reception. The basic principal behind this approach is the shifting in frequency of noise by a few mHz (that's milli-hertz) away from the tuned frequency. This in effect produces a hole in the noise spectrum where weaker signals may be detected. The residual noise is directly proportional to the bandwidth of the hole. Therefore, for wider signals, such as SSB, a modified approach is required. The hole is moved progressively over the required signals bandwidth and the signal is sampled at each step and integrated to reproduce the original wideband signal. A second feature associated with this algorithm deals with variations in propagation. We all know that propagation is largely dependent on the solar flux. Propagation is changed due to the effects of the solar wind. A little known fact is that the remnants of the solar wind that reach the receive antenna modulates the noise. When the noise is detected this modulation can be interpreted to give information about the condition of the D, E and F layers. This can be used to produce a real-time table of MUF and critical frequencies for each layer. At night some kind of remote sensing with suitable location corrections has to be used. The third and more revolutionary feature, which depends heavily on the previous features, involves the generation and use of virtual transceivers or individual ionosphere layer repeaters. As an example we will assume a distant CW signal is transmitted on 21.110Mhz and the MUF is around 15.000Mhz. The signal will not be refracted to our receiving station and most of it is lost in space. If we transmit a heterodyning carrier pulse on 14.110MHz, which is below the MUF, then it will mix with the transmitted signal and produce a weak signal pulse at 7.000MHz which is reflected back to the receiving station. There is a time delay between the sending of the pulse and receiving the return pulse. The transmitted pulse length is made less than this delay so that the 7.000MHz return pulse may be received between transmit pulses. This process is repeated and the received signals integrated to reconstitute the original signal sent. There are some operating problems to be worked out with the transmission of multiple heterodyning carriers. Thus only a few K3's are expected be loaded with the new firmware until these problems are resolved (spread spectrum has been suggested). New menu items may be added to include these features in a future K3 DSP firmware update. MUF OFF/AUTO and 1-10 will vary the effect of received signals using simulated MUF values. This can improve signals on all bands. Unfortunately this enhancement is not reciprocal and only works on receive. Thus K3 to K3 contacts should have a distinct advantage. The algorithms used are not open source as these features are expected to have a huge affect on the whole radio communications industry. It is still in the early beta-test stages. The above is a rough summary of the original unwinese language document submitted by Professor G. E. T. Morsig who is the 1st Associate Professor of Radio at the Institute of Ljubljana. He will be very interested in your assessment of this system and may be contacted via F(zero)OL (qrz.com). My apologies if I have made a minor slip or two in the translation. Unwinese is not an easy language to translate. Please do not contact Elecraft for this firmware until there is an official statement! 73 and Enjoy Tony Fegan VE3QF (anxiously awaiting further developments!) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 RX below 500 kc/s
For very slow data modes. A pal used 100W to a low antenna (probably a few mW erp) and several minutes per character, in a few Hz channel, worked a guy several hundred miles away. He is looking to temperature control the crystals in his rig and pc. David G3UNA Jan Erik Holm sm2...@telia.com wrote: Mike-WE0H wrote: Frequency stability is extremely important for operating on those LF MF bands. Can´t see why it´s more important on LF then on HF/VHF/UHF however frequency stability is always good. Jim SM2EKM __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] What is the status of Elecraft's power amps
Less than two months before Dayton and on the first of April, if for no other reasons, I probably should be asking this... Is there any chance that the KPA-1500 and/or KPA-800 power amplifiers will be released in the foreseeable future, or has the project been shelved permanently? vy 73 de toby __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3
I'll be vacationing in NC this summer at a nice cottage in the mountains. Taking my K3, what is the best portable antenna to take with me for that week. There are many and I'm sure there are some strong opinions. Phil - Check out the 40-10 meter portable dipole in the Articles section of my website at www.ad5x.com. That's been my favorite portable antenna for quite awhile. When I visit my Dad in New MExico, I use the Portable Vertical (also on my website) as he has no trees or other supports on his property. Phil - AD5X __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Calibrate Solder Station
Walter, For many years I have used a Weller TC 3001 iron (temperature control) with various types of tip, and its WTCP 51 power supply, and I have not found a temperature calibration unit to be necessary. This iron has been and is used a lot while building homebrew equipment, most using SMD components, which includes the soldering of the seams of metal enclosures used for shielding. 73, Geoff GM4ESD Walter V. Gilles wrote on Wednesday, April 01, 2009, at 12:06 AM Greetings, I'm going to purchase a solder station, probably one of the popular Weller or Hakko units, with additional tips. Both manufacturers sell accessories to calibrate the stations. Some recommend performing a temp calibration whenever you replace the tip or the iron. All well and good until you see the cost of these calibration (test) units. Would it be prudent to forego the calibrations altogether, and just swap tips as needed, and rely on the initial cal to keep it in the ballpark? I'm guessing after getting used to the station, you will have a sense of proper temp for a particular job, and could just tweak the temp setting up or down as needed without really getting into the calibration arena. Just wanted to see what folks thought about calibration and if it was worth it. Thanks. 73 Walter, WB2IDK (ex-N0DZJ) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Calibrate Solder Station
Walter, Your instincts are correct: I'm guessing after getting used to the station, you will have a sense of proper temp for a particular job, and could just tweak the temp setting up or down as needed without really getting into the calibration arena. Unless you are in a critical manufacturing environment, the precise temperature is meaningless. Turn it up only as high as you need it to melt and flow the solder into the connection. 73, Bob W5OV -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Walter V. Gilles Sent: Tuesday, March 31, 2009 6:06 PM To: elecraft@mailman.qth.net Subject: [Elecraft] Calibrate Solder Station Greetings, I'm going to purchase a solder station, probably one of the popular Weller or Hakko units, with additional tips. Both manufacturers sell accessories to calibrate the stations. Some recommend performing a temp calibration whenever you replace the tip or the iron. All well and good until you see the cost of these calibration (test) units. Would it be prudent to forego the calibrations altogether, and just swap tips as needed, and rely on the initial cal to keep it in the ballpark? I'm guessing after getting used to the station, you will have a sense of proper temp for a particular job, and could just tweak the temp setting up or down as needed without really getting into the calibration arena. Just wanted to see what folks thought about calibration and if it was worth it. Thanks. 73 Walter, WB2IDK (ex-N0DZJ) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] K3 3.04 FW glitch
LINE OUT = PHONES is stuck. Can't change it back to NOR. Other menu items can be set/reset OK. Anybody else seeing this? Reloaded 3.04 and problem still there. 73 de Brian/K3KO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 3.04 FW glitch
LINE OUT = PHONES is stuck. Can't change it back to NOR. Other menu items can be set/reset OK. Does tapping the 1 toggle it? Seems to work OK here. 73, Lyle KK7P __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 3.04 FW glitch
Tapping 1 toggles it between PHONES and NOR for me . Bob W6VY - Original Message - From: Brian Alsop als...@nc.rr.com To: elecraft@mailman.qth.net Sent: Wednesday, April 01, 2009 6:16 AM Subject: [Elecraft] K3 3.04 FW glitch LINE OUT = PHONES is stuck. Can't change it back to NOR. Other menu items can be set/reset OK. Anybody else seeing this? Reloaded 3.04 and problem still there. 73 de Brian/K3KO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 3.04 FW glitch
Tnx all. Of course it works! Done in by thinking you know the radio. Twisting the main tuning knob does not work and isn't supposed to. 73 de Brian Robert Dorchuck wrote: Tapping 1 toggles it between PHONES and NOR for me . Bob W6VY - Original Message - From: Brian Alsop als...@nc.rr.com To: elecraft@mailman.qth.net Sent: Wednesday, April 01, 2009 6:16 AM Subject: [Elecraft] K3 3.04 FW glitch LINE OUT = PHONES is stuck. Can't change it back to NOR. Other menu items can be set/reset OK. Anybody else seeing this? Reloaded 3.04 and problem still there. 73 de Brian/K3KO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] K-1 For Sale- Price Reduced
I sent this previously but due to lack of response I am dropping the price from $375 to $350 including shipping before listing it on the auction site. I have a very nice 4 band Elecraft K-1 for sale. It is an early one, SN 0069 and is equipped with the 4 band module for 40, 30, 20 and 15 meters, internal battery pack, tilt base with both short and long arms as well as the original spiral bound assembly manual and a Revision E manual. The firmware is 1.09. I am now asking $350 including shipping to US addresses. Overseas shipping at cost. I can accept PayPal though I prefer a USPS money order and possibly a check as well. If interested please respond off list to n...@verizon.net. 73, Roger, NJ2R __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] What is the status of Elecraft's power amps
I'm glad you asked Toby but I think we will have to wait until Dayton to see! 8( Hopefully the amplifiers availability are announced then as I did plan on ordering the KPA1500 for sureSeems like something will come of them...the initial introduction of the amplifiers came at Dayton 2 years ago I believe. Good luck Is there any chance that the KPA-1500 and/or KPA-800 power amplifiers will be released in the foreseeable future, or has the project been shelved permanently? vy 73 de toby __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html -- View this message in context: http://n2.nabble.com/What-is-the-status-of-Elecraft%27s-power-amps-tp2568268p2570465.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] What is the status of Elecraft's power amps
Perhaps they ... or better yet ... the panadapter will appear at Visalia ... as was the case for the K3. (:-) 73! Ken Kopp - K0PP elecraftcov...@rfwave.net http://tinyurl.com/7lm3m5 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] What is the status of Elecraft's power amps
Hi Ken, The Panadapter would be ok also!!! 73 Larry K1UO - Original Message - From: Ken Kopp-3 (via Nabble) To: Larry K1UO Sent: Wednesday, April 01, 2009 1:39 PM Subject: [Elecraft] What is the status of Elecraft's power amps Perhaps they ... or better yet ... the panadapter will appear at Visalia ... as was the case for the K3. (:-) 73! Ken Kopp - K0PP elecraftcov...@... http://tinyurl.com/7lm3m5 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:elecr...@... This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html -- This email is a reply to your post @ http://n2.nabble.com/What-is-the-status-of-Elecraft%27s-power-amps-tp2568268p2570522.html You can reply by email or by visting the link above. -- View this message in context: http://n2.nabble.com/What-is-the-status-of-Elecraft%27s-power-amps-tp2568268p2570553.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] KNB2 Noise Blanker
Hello Elecrafters, In the archives there are several messages regarding the effectiveness or lack of effectiveness of the KNB2 noise blanker for the K2. Having just finished assembly of one for my recently completed K2 I wanted to share my findings. This kit is an easy build with only three simple toroid coils to wind. There are no transformers. The one SMD device is pre-installed on its own small circuit board and caused no assembly problems. Installation of the KNB2 caused a very small loss of sensitivity in the K2. This is not noticeable with off the air signals but was detectable when checking MDS with a calibrated signal generator. Sensitivity is still more than adequate for the HF bands. The noise blanker is very effective in reducing my local power line noise. Weak signals on 20 meters that were not copyable before are now Q-5. According to the S meter the noise is being reduced from 20 dB over S9 to a level of only about S3 with no noticiable signal distortion. I am very pleased with this accessories for my K2. 73, Bill - K6WLM __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna
On Tue, 31 Mar 2009 18:43:39 -0700, Ron D'Eau Claire wrote: But it *IS* a ground for RF purposes Nope! It has NO relationship with the earth, nor is one needed. This use of the word ground is an ongoing source of confusion and misunderstandings. Hams to go extremes to install ground rods, thinking that it will improve the performance of their antennas or make their radios quieter or fix RFI. A connection to earth does NOT do any of those things. It IS critical for lightning protection. That's all. Radials are not GROUND in any sense. They are part of the antenna! Indeed, their purpose is to intercept the fields produced by the antenna and by providing a low resistance path for return currents, prevent those fields from producing current in the lossy earth. There is an excellent discussion of this by Rudy Severns, N6LF, both in the ARRL Antenna Book and on his website. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] Portable Antennas
On Wed, 1 Apr 2009 06:10:06 -0500, Phil Debbie Salas wrote: I'll be vacationing in NC this summer at a nice cottage in the mountains. Taking my K3, what is the best portable antenna to take with me for that week. My strong opinion is to be prepared for a variety of possible conditions with some simple solutions. One very useful piece, if you can transport it, is the DK9SQ 10M long telescoping mast. It's a nine-section fibreglas mast that comes in a very nice outer tube that's about 42 inches long. Tape a suitable length of wire to it and you've got half of an antenna that you stick stick out a window or set up on a patio. The other half of the antenna is some more wire that you attach to the coax to act as radials or a counterpoise. It's also quite helpful to carry several short lengths of small diameter insulated wire wound on spools. I found a half dozen spools of black #22 at a hamfest, and they are part of my vacation tool kit. You can launch one or more of these wires into a tree with a wrist rocket (advertised in QST and on the internet, it's essentially a very short casting rod and reel). If you're in a building with a steel frame, you can stick that pole or run that wire out the window and the building steel as a counterpoise (run a wire from the radio chassis to the building -- a window frame, or even the green wire of a power outlet). My ham club when I lived back in Chicago holds an annual QRP night in a local park, where members bring a rig and some sort of antenna. I wedged my DK9SQ pole between the top and seat of a picnic table and strung some wire radials on the ground. My K2 with tuner loaded it just fine on 30 and 40M, and I made a half dozen Qs in a little over an hour (including busting a DX pileup in the Carribean). And don't overlook the possibility of hoisting a simple dipole into some trees with a wrist rocket. Take along a length of RG58, and an SO-239 that you can attach wires to. I like these simple wire options a LOT better than loaded whips like mobile antennas and the Buddy Pole simply because loaded whips are 1) lossy and 2) very narrow band. When we're running QRP, the last thing we need is loss. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] Your suggestions: side-by-side reciever CW comparison
Hey gang, I'm looking for suggestions. I would like to do a side-by-side comparison of receiver performance with my second cw rig vs. the k2 without any equipment other than my own ear. Got any suggestions for setup etc? Thanks N1BBR Duane -- bw...@fastmail.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Your suggestions: side-by-side reciever CW comparison
What is your second cw rig? Steve Ellington n...@carolina.rr.com - Original Message - From: dw bw...@fastmail.fm To: Elecraft_List elecraft@mailman.qth.net Sent: Wednesday, April 01, 2009 3:23 PM Subject: [Elecraft] Your suggestions: side-by-side reciever CW comparison Hey gang, I'm looking for suggestions. I would like to do a side-by-side comparison of receiver performance with my second cw rig vs. the k2 without any equipment other than my own ear. Got any suggestions for setup etc? Thanks N1BBR Duane -- bw...@fastmail.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Your suggestions: side-by-side reciever CW comparison
Here's my technique: 1. Connect both rigs to the same antenna, through some sort of (jury-rigged) Y arrangement. 2. Feed the speaker outputs from both rigs into separate inputs on my Behringer or Mackie mixer. 3. Set rig's AF gains to about 1/2 way point to improve AF S/N ratio. 4. Trim the inputs on the mixing board to get both channels to the same level. 5. Set both channel EQ control to the same (flat). 5. Plug headphones into the mixer. 6. Tune both rigs to the same signal. Now, to compare the rigs, you adjust the channel volume controls on the mixer. Listen to each channel by itself or put one rig in the L ear and one in the R. You will definitely hear differences that you wouldn't hear if you listened to one rig for 30 minutes, then disconnected, hooked up the 2nd rig and listened for 30 minutes. Oh, wait, you wanted a suggestion that didn't involve any equipment. - Keith N1AS - - K3 711 - -Original Message- I'm looking for suggestions. I would like to do a side-by-side comparison of receiver performance with my second cw rig vs. the k2 without any equipment other than my own ear. Got any suggestions for setup etc? Thanks N1BBR Duane __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Portable Antennas
The HFPACK yahoo group has conducted tests of shortened antennas which seem to indicate that losses in loaded antennas are quite small when the total antenna length is at least half the full length. They compared to reference full-length antennas *at the same height*. As to bandwidth, the automatic tuner in my KX1 easily takes care of that. That said, I use both a BuddiPole and wire antennas, and often I prefer the wires, depending on the situation. Over Arizona's dry and rocky ground I often prefer horizontal polarization. For 40m I replace the BuddiPole standard whips by the 6-section optional whips that measure about 9'4, and I put extra tubing sections between the center and the loading coils. (For 20 m this configuration is almost full size.) It does stay up in calm weather on the BuddiPole tripod with the short mast without guying. But his configuration weights a lot more than a wire dipole! For 20 m horizontal polarization, the standard BuddiPole works fine, but weight still tends to favor wires in an inverted Vee configuration, particularly if you use a small and light support pole, that may still be taller than the BuddiPole short mast. (Some of the height advantage is negated by the use of an inverted Vee vs the straight BuddiPole.) Where weight is not a consideration I may use my DK9SQ mast for an inverted Vee. In fact I use two of them in a beam configuration for 40 m. Using a 25 ft spacing and a reflector plus driven element I get an almost perfect match to 50 ohms. On the other hand a fiberglass pole can be awkward to carry around. For a recent hiking trip I put the longer BuddiPole configuration easily in a backpack, worked a JA on 20 m in the afternoon using the KX1 at 2W. Where soil conditions favor vertical polarization, the BuddiPole can be configured as a vertical. The counterpoise can be the other half of the dipole mounted horizontally. However, this configuration is heavy, poorly balanced and requires guying. A single wire counterpoise lying on the ground is better but a little less efficient. Two counterpoise wires stretched in opposite directions is best. Using wire counterpoises, the BuddiPole vertical is rather light; and where the soil is relatively conductive I think this configuration is quite good provided you configure it physically long enough for the band to be used. 73, Erik K7TV Jim Brown wrote: I like these simple wire options a LOT better than loaded whips like mobile antennas and the Buddy Pole simply because loaded whips are 1) lossy and 2) very narrow band. When we're running QRP, the last thing we need is loss. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna
Jim, IMX it's a mistake to equate RF ground with an Earth connection. An RF ground is just a low-impedance, low-reactance current sink for RF. Of course it is an integral part of the antenna circuit. An RF ground would not be expected to radiate, and most counterpoise or radial setups don't radiate a significant amount of energy*: 1) Counterpoises near the Earth and on-ground radials tend to couple all their energy into the lossy dielectric of the Earth, never to be seen again. This is how BCB stations achieve a good RF ground generally using 120 0.2 wavelength radials around their towers to couple the RF into the Earth. 2) Elevated radials will radiate a lot unless they are carefully balanced and symmetrical so legs produce RF fields that cancel each other outside of the immediate area of the antenna. Such radials, like any RF ground, *are* part of the antenna circuit but, when properly designed, they are a non-radiating current sink. In the common ground plane designs, they also decouple the radiating element from the feed line, providing an RF ground not only for the radiator but also grounding the feed line at the antenna so RF currents don't flow down the outside of the coax shield. Ron AC7AC * Students have asked me what happens if they use only one radial with a 1/4 wave antenna. I reply that if they make it 1/4 wave long, then elevate them both into the air and arrange them to run in opposite directions for maximum efficiency, one 'radial' works just fine. If they draw out the antenna I described on paper they'll recognize the common center fed dipole antenna. In that case, there's no problem with the radial radiating. -Original Message- On Tue, 31 Mar 2009 18:43:39 -0700, Ron D'Eau Claire wrote: But it *IS* a ground for RF purposes Nope! It has NO relationship with the earth, nor is one needed. This use of the word ground is an ongoing source of confusion and misunderstandings. Hams to go extremes to install ground rods, thinking that it will improve the performance of their antennas or make their radios quieter or fix RFI. A connection to earth does NOT do any of those things. It IS critical for lightning protection. That's all. Radials are not GROUND in any sense. They are part of the antenna! Indeed, their purpose is to intercept the fields produced by the antenna and by providing a low resistance path for return currents, prevent those fields from producing current in the lossy earth. There is an excellent discussion of this by Rudy Severns, N6LF, both in the ARRL Antenna Book and on his website. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] [K2] CW contest software for Macintosh?
My K2 doesn't have the computer interface. It does key CW nicely in Vox using CocoaModem, though. And CocoaModem has a contest logging feature which seems to work pretty well. Has anyone tried using it for CW contests which don't fit the format of the RTTY contests that are built in (eg CQ WPX, ARRL Field Day)? The macro keys can be edited to send anything, so sending seems to be sufficiently flexible for any contest. But there's a validity check built into the logger that gets unhappy if the exchange looks too different. And yet, cmd-L usually makes it go ahead and log anyway. Does this really work? Alternatively, is there other software for the mac that I should be looking at? RumPED seems to require a MicroHam keyer. I've tried N3FJP running under Crossover, and it logs ok but quits after each QSO, which would be pretty distracting ... Is there a program that works well on the mac which uses the K2 computer interface, if I were to get that? Thanks, Peter N8MHD __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] [K2] CW contest software for Macintosh?
My K2 doesn't have the computer interface. It does key CW nicely in Vox using CocoaModem, though. And CocoaModem has a contest logging feature which seems to work pretty well. Has anyone tried using it for CW contests which don't fit the format of the RTTY contests that are built in (eg CQ WPX, ARRL Field Day)? The macro keys can be edited to send anything, so sending seems to be sufficiently flexible for any contest. But there's a validity check built into the logger that gets unhappy if the exchange looks too different. And yet, cmd-L usually makes it go ahead and log anyway. Does this really work? Alternatively, is there other software for the mac that I should be looking at? RumPED seems to require a MicroHam keyer. I've tried N3FJP running under Crossover, and it logs ok but quits after each QSO, which would be pretty distracting ... Is there a program that works well on the mac which uses the K2 computer interface, if I were to get that? Thanks, Peter N8MHD __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] [OT] K3 IF Output Port
Hi all, I am wanting to use the IF output on the K3 with the installed KVX3 board. My problem is knowing what I need to administer to activate the IF output port. With the K3 as is, I put a 14.270 MHz RF signal into the ANT1 port on the K3. The 14 MHz signal is from an HP 8640 at -120 dBm. The K3 is set to use ANT1. I connect the IF output from the K3 into an HP spectrum analyzer and see no signal at 8.215 MHz. The K3 is tuned to 14.270 MHz USB. So I put Mini Circuits amplifiers with 50 dB total gain between the K3 IF output and the spectrum analyzer. With the amplifiers in the path, I see a signal at – 85 dBm which suggests a signal out of the K3 on the IF output of -135 dBm. If I increase the 14.270 MHz signal by 10 dB I see a 10 dB increase in signal out of the IF output port. Is this right? I would expect a signal out of the IF output with much greater signal strength. In essence, there is a 15 dB loss in the signal path from the antenna jack to the IF output port in my K3 as configured. Is this correct? Is there something I need to administer? Where is this documented? Thank you for your help. Don, N0YE -- View this message in context: http://n2.nabble.com/K3-IF-Output-Port-tp2571810p2571810.html Sent from the [OT] mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Portable Antennas
Eric, K7TV wrote: The HFPACK yahoo group has conducted tests of shortened antennas which seem to indicate that losses in loaded antennas are quite small when the total antenna length is at least half the full length. They compared to reference full-length antennas *at the same height*. As to bandwidth, the automatic tuner in my KX1 easily takes care of that. Quite true according to the literature and the antenna simulator programs (e.g. EZNEC). Since height of a horizontal radiator has a huge impact on the ground reflection gain, it's not uncommon to find a substantial *increase* in signal strength for short-skip operation by shifting to a lower frequency band where the antenna is only 1/4 wavelength long. Actually, such an antenna does not need to use loading coils. The difference in gain between a center fed radiator 1/2 wavelength long and one only 1/4 wavelength long is less than 0.1 dB. Where more losses usually occur is in the feed line and matching network, wherever it exists. Loading the elements or putting some other sort of matching network at the antenna helps provide a low SWR for efficient transmission line operation, but if a low-loss line is used the matching can be done at the rig just as well. In all cases the losses are almost entirely the resistive losses in the conductors, typically the loading coils when they're used or in the feed line if a high SWR exists. Remember, we're not talking about d-c resistance, but RF resistance which is typically much, much greater since 'skin effect' forces all the RF current into the surface of the conductor. Small diameter conductors have far more loss at RF than their d-c resistance might suggest. So it's important that largest possible wire in the smallest possible coil be used for loading. That's obviously a big trade-off, of course, one that Buddipole seems to have handled well. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna
I have to agree with Jim on this one. Perhaps the biggest concept drilled into me by the RF engineers I worked with at Motorola (I was a digital/software/comm engineer) is that there is no such thing as RF ground. RF can, and is, conducted on any path that it wants. This is especially true for the so-called ground and power paths, which while appearing to be well bypassed, still will carry RF currents. The problem was really drilled home when I had to track down a problem with a 450 MHz handheld data transceiver being desensed. The cause was the 250th harmonic of the microcontroller main clock, which placed a 14 uV signal on the receiver input. The signal was being conducted on the system ground, including shielding, and into the receiver front-end. How do you solve it? Shift the crystal frequency when on problematic channels. So, while the concept of a common ground which carries no signals may be an interesting one, in practice it simply does not exist. - Jack Brindle, W6FB. -Original Message- From: Ron D'Eau Claire r...@cobi.biz Sent: Apr 1, 2009 2:00 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna Jim, IMX it's a mistake to equate RF ground with an Earth connection. An RF ground is just a low-impedance, low-reactance current sink for RF. Of course it is an integral part of the antenna circuit. An RF ground would not be expected to radiate, and most counterpoise or radial setups don't radiate a significant amount of energy*: 1) Counterpoises near the Earth and on-ground radials tend to couple all their energy into the lossy dielectric of the Earth, never to be seen again. This is how BCB stations achieve a good RF ground generally using 120 0.2 wavelength radials around their towers to couple the RF into the Earth. 2) Elevated radials will radiate a lot unless they are carefully balanced and symmetrical so legs produce RF fields that cancel each other outside of the immediate area of the antenna. Such radials, like any RF ground, *are* part of the antenna circuit but, when properly designed, they are a non-radiating current sink. In the common ground plane designs, they also decouple the radiating element from the feed line, providing an RF ground not only for the radiator but also grounding the feed line at the antenna so RF currents don't flow down the outside of the coax shield. Ron AC7AC * Students have asked me what happens if they use only one radial with a 1/4 wave antenna. I reply that if they make it 1/4 wave long, then elevate them both into the air and arrange them to run in opposite directions for maximum efficiency, one 'radial' works just fine. If they draw out the antenna I described on paper they'll recognize the common center fed dipole antenna. In that case, there's no problem with the radial radiating. -Original Message- On Tue, 31 Mar 2009 18:43:39 -0700, Ron D'Eau Claire wrote: But it *IS* a ground for RF purposes Nope! It has NO relationship with the earth, nor is one needed. This use of the word ground is an ongoing source of confusion and misunderstandings. Hams to go extremes to install ground rods, thinking that it will improve the performance of their antennas or make their radios quieter or fix RFI. A connection to earth does NOT do any of those things. It IS critical for lightning protection. That's all. Radials are not GROUND in any sense. They are part of the antenna! Indeed, their purpose is to intercept the fields produced by the antenna and by providing a low resistance path for return currents, prevent those fields from producing current in the lossy earth. There is an excellent discussion of this by Rudy Severns, N6LF, both in the ARRL Antenna Book and on his website. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [OT] K3 IF Output Port
Yes, it's 15 dB transfer loss. It's due to the choice of voltage dividing resistors in the J310 source follower stage. Half or a bit more of the loss can be offset with a change in the parts values in the voltage divider feeding the gate. Another option is an outboard amplifier such as the Z1 I've designed. Jack K8ZOA www.cliftonlaboratories.com Don Nelson wrote: Hi all, I am wanting to use the IF output on the K3 with the installed KVX3 board. My problem is knowing what I need to administer to activate the IF output port. With the K3 as is, I put a 14.270 MHz RF signal into the ANT1 port on the K3. The 14 MHz signal is from an HP 8640 at -120 dBm. The K3 is set to use ANT1. I connect the IF output from the K3 into an HP spectrum analyzer and see no signal at 8.215 MHz. The K3 is tuned to 14.270 MHz USB. So I put Mini Circuits amplifiers with 50 dB total gain between the K3 IF output and the spectrum analyzer. With the amplifiers in the path, I see a signal at – 85 dBm which suggests a signal out of the K3 on the IF output of -135 dBm. If I increase the 14.270 MHz signal by 10 dB I see a 10 dB increase in signal out of the IF output port. Is this right? I would expect a signal out of the IF output with much greater signal strength. In essence, there is a 15 dB loss in the signal path from the antenna jack to the IF output port in my K3 as configured. Is this correct? Is there something I need to administer? Where is this documented? Thank you for your help. Don, N0YE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [OT] K3 IF Output Port
...In essence, there is a 15 dB loss in the signal path from the antenna jack to the IF output port in my K3 as configured. Is this correct? Is there something I need to administer? Where is this documented? See URL:http://www.cliftonlaboratories.com/elecraft_k3_and_panadapters.htm 73, Lyle KK7P __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna
Ron, I have been preaching similar points in ham circles for years now - and I find that many hams cannot visualize the difference between a ground (meaning a return path for current) and Mother Earth. Actually any point where the RF current crosses the zero voltage point is a point of RF Ground (it is a potential, not a physical place), and on a balanced antenna it should occur midway between the two sides of the feedpoint - and a vertical with radials *is* a balanced antenna, that is why a balun is needed even on a vertical. The English do distinguish between earthing and grounding, and I do wish that sort of distinction were also in common use in the US, it certainly would help. BTW - elevated radials *do* radiate in the very near field, but when arranged properly (pairs in opposing directions), the radiation is out of phase and will cancel at a distance from the antenna. Your term current sink is not a description I would use. 73, Don W3FPR Ron D'Eau Claire wrote: Jim, IMX it's a mistake to equate RF ground with an Earth connection. An RF ground is just a low-impedance, low-reactance current sink for RF. Of course it is an integral part of the antenna circuit. An RF ground would not be expected to radiate, and most counterpoise or radial setups don't radiate a significant amount of energy*: 1) Counterpoises near the Earth and on-ground radials tend to couple all their energy into the lossy dielectric of the Earth, never to be seen again. This is how BCB stations achieve a good RF ground generally using 120 0.2 wavelength radials around their towers to couple the RF into the Earth. 2) Elevated radials will radiate a lot unless they are carefully balanced and symmetrical so legs produce RF fields that cancel each other outside of the immediate area of the antenna. Such radials, like any RF ground, *are* part of the antenna circuit but, when properly designed, they are a non-radiating current sink. In the common ground plane designs, they also decouple the radiating element from the feed line, providing an RF ground not only for the radiator but also grounding the feed line at the antenna so RF currents don't flow down the outside of the coax shield. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna
Don I'm running a special on RF grounds today. I've carefully measured out some 1/2 wave wires, cut out 6 from the midpoint and offering these for $25. This will totally eliminate the need for multiple radials. Happy April 1. Steve Ellington n...@carolina.rr.com - Original Message - From: Don Wilhelm w3...@embarqmail.com To: Ron D'Eau Claire r...@cobi.biz Cc: elecraft@mailman.qth.net Sent: Wednesday, April 01, 2009 6:12 PM Subject: Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna Ron, I have been preaching similar points in ham circles for years now - and I find that many hams cannot visualize the difference between a ground (meaning a return path for current) and Mother Earth. Actually any point where the RF current crosses the zero voltage point is a point of RF Ground (it is a potential, not a physical place), and on a balanced antenna it should occur midway between the two sides of the feedpoint - and a vertical with radials *is* a balanced antenna, that is why a balun is needed even on a vertical. The English do distinguish between earthing and grounding, and I do wish that sort of distinction were also in common use in the US, it certainly would help. BTW - elevated radials *do* radiate in the very near field, but when arranged properly (pairs in opposing directions), the radiation is out of phase and will cancel at a distance from the antenna. Your term current sink is not a description I would use. 73, Don W3FPR Ron D'Eau Claire wrote: Jim, IMX it's a mistake to equate RF ground with an Earth connection. An RF ground is just a low-impedance, low-reactance current sink for RF. Of course it is an integral part of the antenna circuit. An RF ground would not be expected to radiate, and most counterpoise or radial setups don't radiate a significant amount of energy*: 1) Counterpoises near the Earth and on-ground radials tend to couple all their energy into the lossy dielectric of the Earth, never to be seen again. This is how BCB stations achieve a good RF ground generally using 120 0.2 wavelength radials around their towers to couple the RF into the Earth. 2) Elevated radials will radiate a lot unless they are carefully balanced and symmetrical so legs produce RF fields that cancel each other outside of the immediate area of the antenna. Such radials, like any RF ground, *are* part of the antenna circuit but, when properly designed, they are a non-radiating current sink. In the common ground plane designs, they also decouple the radiating element from the feed line, providing an RF ground not only for the radiator but also grounding the feed line at the antenna so RF currents don't flow down the outside of the coax shield. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] K3 beta firmware rev. 3.06: all-mode squelch; SSB power control improved
K3 beta-test firmware revision 3.05 (with DSP rev 2.12) is now available. For details, see the release notes below. Please send any problem reports to k3supp...@elecraft.com. For instructions on how to load beta firmware, please see: http://www.elecraft.com/K3/k3_software.htm We recommend that you use the latest revision of K3 Utility, which can also be found on the K3 software page. 73, Wayne N6KR * * * MCU 3.06/DSP 2.12 April 1, 2009 * SSB POWER CONTROL: Decreased time that SSB power output takes to reach target when PWR control adjusted. Also eliminated drive level change when ATU TUNE is used. * SQUELCH IN ALL MODES: To use this feature, locate CONFIG:SQ MAIN, then tap '1' until you see ALL. To use the SUB RF/SQL pot to control both main and sub squelch, set CONFIG:SQ MAIN to =SUB POT. (In this case, MAIN RF will control both main and sub RF GAIN.) If you want independent control of main and sub squelch, set SQ MAIN and SQ SUB to numeric values (0 opens the squelch all the way). SQ MAIN and SQ SUB will then be fully independent. They can be assigned to programmable function switches if you use them frequently. (In this case MAIN RF GAIN and SUB RF GAIN are independent, using the lower concentric pots.) --- http://www.elecraft.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Portable Antennas
Ron, I agree on all points. My first antenna was a 40 m dipole with vertical end sections at about 35 ft. Initially I fed it with 300 ribbon cable. Although the antenna was cut roughly for 40m it was probably a bit off. The SWR would have been a minimum of roughly 4:1 but with the vertical ends and moderate height I would guess 6:1 or more. I used a home made balanced tuner and an incandecent bulb to tune for max current. This setup worked, but it worked much better later after I replaced the ribbon cable with home made ladder line. I guess because of this experience I have never again bothered to try 300 ribbon cable in the field. I have used window line in the field, but only for car camping; I consider it too unwieldy for backpacking. For a 1/4 wavelength dipole, in a choice between good high-Q loading coils vs window line, I'll take the loading coils most of the time. However, the very best choice, that I haven't yet tried, may be widely and haphazardly spaced single wires for the feeder. 73, Erik K7TV Quite true according to the literature and the antenna simulator programs (e.g. EZNEC). Since height of a horizontal radiator has a huge impact on the ground reflection gain, it's not uncommon to find a substantial *increase* in signal strength for short-skip operation by shifting to a lower frequency band where the antenna is only 1/4 wavelength long. Actually, such an antenna does not need to use loading coils. The difference in gain between a center fed radiator 1/2 wavelength long and one only 1/4 wavelength long is less than 0.1 dB. Where more losses usually occur is in the feed line and matching network, wherever it exists. Loading the elements or putting some other sort of matching network at the antenna helps provide a low SWR for efficient transmission line operation, but if a low-loss line is used the matching can be done at the rig just as well. In all cases the losses are almost entirely the resistive losses in the conductors, typically the loading coils when they're used or in the feed line if a high SWR exists. Remember, we're not talking about d-c resistance, but RF resistance which is typically much, much greater since 'skin effect' forces all the RF current into the surface of the conductor. Small diameter conductors have far more loss at RF than their d-c resistance might suggest. So it's important that largest possible wire in the smallest possible coil be used for loading. That's obviously a big trade-off, of course, one that Buddipole seems to have handled well. Ron AC7AC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Calibrate Solder Station
The eutectic temperature of most 40/60 solder is around 750. One easy test you could do once you get the tip prepped is to turn the unit off and while it is cooling get a glob of solder to jell on it. Then adjust the heat control to the lowest setting and turn it back on. See what temperature setting is required to liquefy the solder you have on the tip. That setting will probably be your safest for heat sensitive devices. I can tell you though, after 13 years in manufacturing and teaching hi-rel soldering, temperature sensitivity of that resolution would have to be for a device that is pretty vulnerable to heat. A number of descrete devices such as FETs have a general suggested time duration for tip contact. Sensitive DIPS like surface mount ICs quite frequently are soldered criss-cross like you'd do for tightening up the head bolts on an engine. Another way of telling if your tip is too hot is by looking at your joints with a magnifier. Solder inspection in manufacturing is typically done under 14 power if I remember right. Get yourself one of those little eye-scopes. You'll want to have one anyway. Your joints should have a shiny look to them. A technician can often tell if someone has been working on a pcb by looking at the joints. If they look dull or soupy looking, that is a sign if contaminated solder, two many times re-heated, or a tip that is just too hot. Joints from a tip not hot enough may look globby. You could spend up to $200 on a surface probe for a DVM. Digi-key sells one that is just a bead type for $10 TP-29-ND I would check to make sure this comes with a conversion chart. Most of them run negative coefficient. Take a small piece of aluminum and drill a hole in it and squeeze some thermal compound into it. Then insert the thermo-resistor bead into it. Then you can touch the solder tip to it and watch it come to temp. Hope that helps. N1BBR dw -- bw...@fastmail.net __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Portable Antennas
Eric, K7TV wrote: The HFPACK yahoo group has conducted tests of shortened antennas which seem to indicate that losses in loaded antennas are quite small when the total antenna length is at least half the full length. They compared to reference full-length antennas *at the same height*. As to bandwidth, the automatic tuner in my KX1 easily takes care of that I agree. I've used loaded dipoles for both 160M and 80M that are roughly 65% of full size and found them to work quite well. I've also modelled both of these antennas using NEC, using measured values for the coils (both inductance and resistance). The models show that the efficiency of both antennas is only about 0.5 dB less than a full size half wave dipole, and an SWR bandwidth that is less than half that of a full sized half wave dipole. I can't measure the efficiency, but the SWR behaves like the NEC model. I've had both antennas in the air at multiple locations, and can run full legal power into both antennas over all of 160M and 80/75M. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] Elecraft K3/K2 - microHam cable set for sale
Hi -- I have an extra microHam cable set for the Elecraft K3 or K2 available (DB37-EL-K3). List price for a new cable is US$79 + shipping. I will sell for $60 + shipping. Please contact me directly -- please don't respond to the whole list! Thanks. 73, -- Eric K3NA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3 beta firmware rev. 3.06: all-mode squelch; SSB power control improved
I am forever amazed at the extent you all are willing to go to make the K3 and Elecraft exceptional. Thanks! Gary KA1J K3 beta-test firmware revision 3.05 (with DSP rev 2.12) is now available. For details, see the release notes below. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna
Ahh now you are no longer talking about RF ground but the black art of EMI. Its not to difficult to determine RF ground, you have to have very good spatial visualization, the ability to hold the 3D model of the board, chassis and housing in your head, and you need to think like an electron. It takes practice, but being relatively inexperienced i've gotten the hang of it after being involved in the successful design of 2 radios, but then again I have fantastic mentors and elmers. In the end everything is explained by Maxwell's equations and if 1/10th of the ham population took the time to understand how these fantastic formula work and what they mean, 99% of this confusion and most of the half truths you see passed around as 'common knowledge' would disappear. Matt W8ESE Former KD8DAO http://blog.MattIsKichigai.com On Wed, Apr 1, 2009 at 6:04 PM, Jack Brindle jackbrin...@earthlink.net wrote: I have to agree with Jim on this one. Perhaps the biggest concept drilled into me by the RF engineers I worked with at Motorola (I was a digital/software/comm engineer) is that there is no such thing as RF ground. RF can, and is, conducted on any path that it wants. This is especially true for the so-called ground and power paths, which while appearing to be well bypassed, still will carry RF currents. The problem was really drilled home when I had to track down a problem with a 450 MHz handheld data transceiver being desensed. The cause was the 250th harmonic of the microcontroller main clock, which placed a 14 uV signal on the receiver input. The signal was being conducted on the system ground, including shielding, and into the receiver front-end. How do you solve it? Shift the crystal frequency when on problematic channels. So, while the concept of a common ground which carries no signals may be an interesting one, in practice it simply does not exist. - Jack Brindle, W6FB. -Original Message- From: Ron D'Eau Claire r...@cobi.biz Sent: Apr 1, 2009 2:00 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna Jim, IMX it's a mistake to equate RF ground with an Earth connection. An RF ground is just a low-impedance, low-reactance current sink for RF. Of course it is an integral part of the antenna circuit. An RF ground would not be expected to radiate, and most counterpoise or radial setups don't radiate a significant amount of energy*: 1) Counterpoises near the Earth and on-ground radials tend to couple all their energy into the lossy dielectric of the Earth, never to be seen again. This is how BCB stations achieve a good RF ground generally using 120 0.2 wavelength radials around their towers to couple the RF into the Earth. 2) Elevated radials will radiate a lot unless they are carefully balanced and symmetrical so legs produce RF fields that cancel each other outside of the immediate area of the antenna. Such radials, like any RF ground, *are* part of the antenna circuit but, when properly designed, they are a non-radiating current sink. In the common ground plane designs, they also decouple the radiating element from the feed line, providing an RF ground not only for the radiator but also grounding the feed line at the antenna so RF currents don't flow down the outside of the coax shield. Ron AC7AC * Students have asked me what happens if they use only one radial with a 1/4 wave antenna. I reply that if they make it 1/4 wave long, then elevate them both into the air and arrange them to run in opposite directions for maximum efficiency, one 'radial' works just fine. If they draw out the antenna I described on paper they'll recognize the common center fed dipole antenna. In that case, there's no problem with the radial radiating. -Original Message- On Tue, 31 Mar 2009 18:43:39 -0700, Ron D'Eau Claire wrote: But it *IS* a ground for RF purposes Nope! It has NO relationship with the earth, nor is one needed. This use of the word ground is an ongoing source of confusion and misunderstandings. Hams to go extremes to install ground rods, thinking that it will improve the performance of their antennas or make their radios quieter or fix RFI. A connection to earth does NOT do any of those things. It IS critical for lightning protection. That's all. Radials are not GROUND in any sense. They are part of the antenna! Indeed, their purpose is to intercept the fields produced by the antenna and by providing a low resistance path for return currents, prevent those fields from producing current in the lossy earth. There is an excellent discussion of this by Rudy Severns, N6LF, both in the ARRL Antenna Book and on his website. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support
Re: [Elecraft] BL-2 Connection To An Unbalanced Wire Antenna
Matt, Many years ago, I had an EE professor who said it right - there are two disciplines in EE that need to consider 4 dimensions - the 3 dimensions of space as well as that position in time. One is 3 phase motor analysis and the other is analysis of an RF wave in space (or on antennas). I have found repeatably that his statement is quite true. The added time element makes the subject complex and difficult to visualize. The discussion of RF ground is related. 73, Don W3FPR Matt Palmer wrote: Ahh now you are no longer talking about RF ground but the black art of EMI. Its not to difficult to determine RF ground, you have to have very good spatial visualization, the ability to hold the 3D model of the board, chassis and housing in your head, and you need to think like an electron. It takes practice, but being relatively inexperienced i've gotten the hang of it after being involved in the successful design of 2 radios, but then again I have fantastic mentors and elmers. In the end everything is explained by Maxwell's equations and if 1/10th of the ham population took the time to understand how these fantastic formula work and what they mean, 99% of this confusion and most of the half truths you see passed around as 'common knowledge' would disappear. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] test
test - please disregard - KL7CC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] What is the status of Elecraft's power amps
I'm glad someone other than me asked this time! Here's hoping (again) that we see these released at Dayton this year: Lou, W0FK Less than two months before Dayton and on the first of April, if for no other reasons, I probably should be asking this... Is there any chance that the KPA-1500 and/or KPA-800 power amplifiers will be released in the foreseeable future, or has the project been shelved permanently? vy 73 de toby __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html - St. Louis, MO K3 #2513 -- View this message in context: http://n2.nabble.com/What-is-the-status-of-Elecraft%27s-power-amps-tp2568268p2573211.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
