[Elecraft] K1 and K2 Receiver Performance
The K1 receiver performance is not in the same class as the K2 and other high performance receivers. Your TS830 has a good receiver, much better than the K1, but probably short of the K2. At the Duke City Hamfest a couple of years ago, Fred, KT5X, had his K2 and a 20 M Moxon set up. I brought myy K1. The hamfest station, N5M was operating on 14.025 about 100 ft away. With the hamfest station off the side of the Moxon, the K2 could operate at 14.030 with no trace of N5M at all, and still operate comfortably with some trace of N5M at a couple of kilohertz away. With my K1, I still heard it on 14.060. The only way I could work weak to moderately strong signals at 14.060 was with the attentuator kicked in, and even then there were some artifacts. This made a beliver out of me about the K2's strong front end. The K1 does not do well in crowded strong signal conditions. This is aggravated by the inability to turn the AGC Off without going through the menus or converting the XIT button to AGC, which one can do. However, the XIT is useful in crowded pileup conditions, as is the ability to turn off the AGC. The price the K2 pays for its superb performance is a 5X or so increase in power dissipation on receive. The K2 really shines with its bulletprroof front end, which is the key to good receiver performance. Then it becomes a rather ordinary receiver: its crystal filter has a poorer shape factor than many other modern rigsm and is asymmetrical; standard as well as optional aftermarket filters available for many rigs including your TS-830 are much better than the K2's filter, and there is no passband tuning/IF shift like most modern rigs have. DSP or any audio filtering is optional, and without the DSP there is no notch/peak filter. The barebones K2 receiver does not have many features we take for granted in today's receivers, inncluding SSB, a noise blanker, and audio (both analog and digital) filtering. These are all options. I doubt if there are many barebones K2s out there. Having said all this, we at AA5B, running a barebones 2 band K1 finished 2nd nationwide in 1A Battery FD this year running my K1. With an external keyer, required for competitive contestingm it gave a good account of itself. Don't get me wrong, one of these days I will get a K2. Maybe in May, when my youngest daughter graduates from college. :^)= In the meantime I am more than happy with my TS-850, which has a really good receiver, and my OHR 500 and Classic, both which have receivers with very good front ends. For high performance in a protable/small rig it can't be beat. But it is not the ultimate receiver. I suspect that the K3 will be though. :^)= - Dr. Megacycle KK6MC/5 -- James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ 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] Antenna Question
Tom - You should use a 1:1 balun to feed the balanced line with the K2 tuner. You can easily make one by wrapping a dozen or so turns of RG-58 through a type 43 or 61 core FT140 or larger. Diz, at http://partsandkits.com/index.asp is a good source of these toroids. Alternately, you can slip a half dozen type 73 ferrite beads over RG-58. The beads are available from Mouser as part number 2643540002. COvering hte whole assembly wiht heatchrink tubing keeps things from moving around. I would avoid using a 4:1 balun. On those bands where the antenna impedance is low the balun will make it lower and harder to match and will result in more loss in the tuner. If you have trouble tuning the antenna, you can add an additional section of feeder to help the match. Others have popinted this out sa well. If you feed the antenna with balanced feeder you don't need to make the dipole resonant, yoiu can make it any convenient length. Some lengths have advantages over than others, but if you make it shorter than about 0.4 wavelengths, SWR on even a balanced feeder will be high and losses will be large for long runs. - Dr. Megacycle KK6MC/5 ___ 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] Low antennas in high places
Vic - I often operate QRP field operations from such a location at Gallisteo Dam. It has a long steeply sloping ground to the East and Northeast. I use an inverted vee for 40 M and 20 M at 24 feet in a painters pole. Propagation is great and I do pretty well in the QRP field contests. It is worth looking for such locations and trying them out. If you have any further questions drop me an e-mail. - Duffey -- James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ 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] Internal battery question
Charles - A well charged Gel Cell should have a voltage in the neighborhood of 13.2 to 13.8 V. It appears that you did not fully charge the battery, or the battery is incapable of accepting a good charge. Others have pointed this out as well, you need a charger/supply that is capable of of overcoming the Schottky diode voltage drop in the K-2. You might want to try charging the battery out of the K2 to see if it will take a charge and how that will last when reinstalled in tthe K2. The battery in the K2 is a bit undersized for extended QRP use at 5 W. This is exacerbated by the common use of float charging, which does not fully charge a Gel-Cell, or takes forever to do it. The use of a smart charger is recommended. There are some issues with using a smart charger, but they are covered in the technotes area of the Elecraaft site. - Dr. Megacycle KK6MC/ -- James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ 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] Interesting Tuner applet
Daan - Here is the match I get for your problem: Input C 226.6 pF Coil 1.2 uH Output C 174.7 pF SWR 1.0 Percent loss 1.0 dB loss 0.0 (actually this means less than 0.1, teh lowest value the applet shows) It is a bit different than yours and the automatch, but it is low none the less. I get the same automatch that you do. This points out that although a T-match can achieve a non unique match, there usually is not a significant difference in loss in these matches. Here is how I tune a T-match tuner, and the applet as well. 1. Set all controls at maximum. 2. Reduce the inductance untill you see a dip. It might be a shallow dip, or it may be a deep dip, but you should see a dip. 3. Reduce the output cap until you see a dip. 4. Reduce the input cap until you see a dip. 5. Tweak the inductor if the dip is not at 1:1. 6. Go back and tweak the output cap, input cap, and inductor to get to the lowest SWR. 7. If you still have a high SWR, see which control impacts the SWR the most. Turn it one direction off the dip. Tweak the other two controls in turn to get a dip. If the SWR is lower than when you started, turn the initial control in the same direction and tweak the other two controls until you get a new dip. Repeat unitl you get the lowest SWR. If the SWR is higher than before, turn the control in the opposite direction and proceed as above. 8. You may find that only two of the three controls affect the SWR dip. If that is the case, concentrate on those two. This all becomes second nature after doing it several times. I keep a cheat sheet on top of the tuner with the correct settings for each band/antenna combination. That makes band changes quick. You can also use those Post It pointers that administrative assistants use to show you where to sign a document to indicate proper settings. I hope that this helps. - Dr. Megacycle KK6MC/5 -- James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ 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] Antenna Analyzers
After 25 years of using a home built noise bridge to tune antennas, I love the MFJ 259B that my wife gave me for Christmas. It is a wonderful tool. I have had no problems with mine. It does eat batteries though, and there are a few on the list who remember Doug Hendricks, Dave Gauding and myself doing our best the Three Stooges act tuning one of the first NorCal Doublets at W5JAY's house 3 or 4 years back at Arkiecon. Among the comedy of errors included using W5JAY's MFJ 259B connected to an 24 AH Gel Cell. I got tired of taking the back off to change those damn batteries was Jay's explanation. The tool is no better than the craftsman using it. An antenna analyzer will not automatically help you to build a better antenna if you don't understand basic antenna and transmission line principles, but it will help you to understand those principles. I find the MFJ very valuable in the field to quickly verify that the antenna is operating OK. - Dr. Megacycle KK6MC/5 -- James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ 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] Winding Toroids
A crochet hook makes a fine toroid winding tool. I use a partially straightened out paper clip. A few years back I gave a talk on baluns at the SW ARRL convention in Riverside. Some of you may remember it. I demonstrated how to wind a torroid to a large group using a roll of toilet paper for the core, a piece of rope for the wire and a straightened out coat hanger as the tool. People got the picture quickly. This is a good demo the next time someone at your club says they don't build because winding toroids is a pain. :^)= There used to be pictures of me doing this demo on the net, but thankfully they have evaporated. - Dr. Megacycle KK6MC/5 __ James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ 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] K1 enthusiast wonders ??
Let me present a dissenting point of view on the K1. I am the fourth owner of K-1 SN0004 with a 40/20 M module. I have had it for 2 years. I have found that the more I use it the less I like it. I find the K1 both too much radio and too little radio at the same time. I use it primarily for portable operation. As I don't use it all the time in the shack, I find that I need the reference card to recall all of the functions when I use it in the field. Being menu driven and with many of the switches having several functions I often make mistakes. The code speed goes up when I try to change filter settings for example. I don't need all of those functions in a portable contest radio, and I think that cramming them all into a small radio significantly detracts from the ability to seamless operate the radio. Thus, the radio is too much. But, there are significant performance compromises made. There is no RF gain. The NE602 front end mixer has problems in crowded band conditions. These two issues are exasperated by the fact that the AGC cannot be turned off without going into the menus. The filter has a pretty poor shape factor, with a very gentle roll off on the high side. The fact that the filter is adjustable means that optimum peformance is not possible at any bandwidth. The built in keyer requires 2 key strokes to send what is in memory, a big delay in contests. I bought the K-1 to replace an aging OHR Classic, also a 20 M and 40 M rig. I find myself returning to the OHR more and more. It is a simple receiver with no bells and whistles. But it uses a crunch proof diode balanced mixer in the front end that runs circles around the K1's NE602. After a few hours with the K-1 on 40 M for Field Day, we switched to the OHR and were much happier with its performance. As the OHR does not have an RF Gain control and the AGC is not switchable, the preference for the OHR is likely due to the higher performing front end and better IF filter. We eventually replaced the OHR with a K2 when the 15 M station QRTed at dark. It was preferable to both the K1 and the OHR. There are some nice features of the K1. The tilt stand is very nice in getting the rig off the table and at eye level, a common problem with QRP rigs. The provision for repetitive CQing is nice on sparsely populated bands during contests. I like the provision to monitor the battery voltage. The audio is generous and much better than the K2. The rig has generous power output and 5 watts is possible on all bands. The built in power meter is nice to have. I must admit that many of these opinions may be colored by a feeling of betrayal by the K1. It is the only rig to have failed me in the field. At the start of Field Day it failed to work on 40 M. 20 M was fine. After opening the rig, removing the filter board, inspecting it to find nothing obviously wrong, cleaning it, and reseating it; it again worked OK. Don't know what the problem was, but it left me with less confidence in the K1 than I had before. I don't need that kind of stress prior to a major operating event. I have often thought of upgrading with a 4 band module and the built in tuner. I believe that would also require a firmware upgrade in a rig as old as mine. The total for these upgrades is about 90% of what I paid for the rig, and I question if putting that much money into a rig I am not real happy with is worth it to me. But it does point out the fact that adding options quickly raises the price of an Elecraft rig. Having said all that, I realize that rig preference is a personal thing. Most are happy with their K1s. The K1 does not really fit what I am looking for in a portable rig for contesting. The more I use it, the more these shortcomings are apparent to me. I have decided that performance is more important to me than the bells and whistles of the K1. I respect the opinions of those who love their K1s and this is not meant to denigrate them. I just am not one of them. - Dr. Megacycle KK6MC/5 __ James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ 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] Batteryt Life
I have posted how to calculate battery life here before. John gave a pretty good reply, but there are a couple of other points that should be made. 1. A lead acid battery is rated assuming the current is drawn at the 20 hour rate. If you draw more current than this, you will get less capacity from the battery. At the 10 hour rate, the capacity is diminished by about 10%, at the 5 hour rate it is diminished by 25%, and at the 1 hour rate it is diminished by 40%. 2. It is difficult to fully charge a lead-acid battery by trickle charging it at a constant voltage. Trickle charging at a constant voltage will only restore about 85% of the battery's capacity. To do better than this you need to use one of the smart chargers or triple mode charges such as those based on the Unitrode (now TI?) 3906. If you do not realize this you can get substantially less life from the battery than you anticipate. My K-1 draws about 70 mA on receive with the headphones and volume set for comfortable listening in the field. The transmitter draws about 1.1 A on transmit. With half of the time spent listening, and half of the time spent transmitting with a 40% duty cycle I get an average current draw of 0.276 A. If you constant voltage charged the battery, you will have a 20 hour capacity of 3.4 AH. At a current draw of 276 mA, I am pulling current out of the battery at a 12 hour rate. Since this is greater than the 20 hour rate our capacity will be diminished by about 10%. Reducing the capacity by this amount leaves 3.06 AH capacity. Dividing by the average current draw, 0.276 A, we get 11 hours capacity. Of course, in actual operation the average current draw can vary quite a bit, usually on the down side (we forgot to include bathroom time and emergency antenna repairs in the above calculations) so it is best to only use these numbers as a guide and not to really expect to get that last hour or half hour out of the battery. I hope that this helps. - Dr. Megacycle KK6MC/5 __ James R. Duffey KK6MC/5 Cedar Crest NM 87008 DM65 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
