[Elecraft] P3 phantom carrier
Just recently my P3 is showing a carrier with-in the SSB pass band. It is quite strong and it is always there, even with no antenna connected. It is particularly annoying on CW, where it falls exactly on the expected receive frequency. It moves with the VFO, so it is always in the same place in the pass band, but it does not produce a tone in the headphones. I seem to remember reading that there is an adjustment to get rid of this, but I can’t find it in the P3 or K3 manual. Roger, VK4YB __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] K3 and KX3 on 630m/2200m
I have been running both my K3 and KX3 on 630m and 2200m for the last 18 months using commercially available Transverters. The transverters require 5 watts of drive and it is easy to adjust to this output on both of the Elecraft rigs. Just search for 630m band transverter, or 2200m band transverter. OK, I confess, I own Monitor Sensors! 73 Roger, VK4YB. __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] Scam?
I have received an email which purports to come from Elecraft. The return address goes to N9SC. It directs one to a suspicious looking web site. I have not followed this link. Roger Crofts, VK4YB __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] When is mode A not mode A?
I love my KX3 and its little paddle. Unfortunately my keying is full of mistakes. When I send the letter C for example, it often comes out as CT or K. I thought the KX3 must be set to mode B keying, but no, it was on mode A. I originally learnt to send on an ETM-3b squeeze keyer many moons ago. The ETM-3b is a mode A keyer. I tried plugging a Bencher paddle into the KX3 but the problem remained, so the paddle is not the problem. Is the mode A, that I am used to, somehow different to the mode A in the KX3? Roger, VK4YB __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] re K3 timekeeping
My K3 clock loses about 9 seconds per day. This is not quite as bad as Arlen's clock, but it is still annoying. I run quite a few skeds and nets and I like to be spot on time. Dear Wayne, are you listening? We need your help to write a little routine that goes like this:- When the K3 powers up, it reads an eeprom location which stores the last turn-on time. It calculates how long ago that was from the present time. It reads the correction factor in tenths of seconds per 24 hours from another eeprom location. It calculates the correction required in tenths of a second and updates the clock accordingly. It stores the tenths of seconds remainder in another location ready to be taken into account in the next calculation. Finally it updates the last turn-on time. Of course you will realize that an extra menu item will also be needed, so users can enter their clock correction factor. A single byte can store a correction factor from -12.7 to +12.7 seconds per 24 hours. With this software addition, the K3 will become a superb chronometer. Perhaps once a year the user will need to tweak the correction factor to allow for crystal aging in the real-time clock. 73 Roger, VK4YB __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] Elecraft order tracking numbers
My last two orders from Elecraft came by U.S. Postal Service Priority Mail International. When I checked the tracking numbers, I discovered the first parcel had been delivered to Brazil and the second one to the Russian Federation. As I live in Australia, this was a bit of a worry. It turns out that the tracking numbers, issued by endicia, are re-used after a year or two. My parcels had the same tracking numbers and arrived safely a few days later. The tracking number is 13 characters long and consists of a mixture of letters and numbers. There are thus 170,581,728,179,578,208,256 possible combinations AND they need to re-use some of them! That's almost enough tracking numbers for every atom in the universe (well, not actually, that would be one followed by 78 zeros). Anyway, you have been warned. 73 Roger, VK4YB __ 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 Main and Sub BFO's
Following the recent discissions of optimum CW pitch, I wondered if the brain might be better able to discriminate the wanted signal from close-in QRM by inverting the sideband to one ear. Only the wanted signal would have the same pitch in both ears. I set-up the main and sub receivers to a separation of double the pitch frequency and then linked the VFOs. So far so good. Then I inverted the sideband on the sub receiver. But alas, the sideband on the main receiver inverted at the same time. Even using "b Set" I could not get the BFOs on the main and sub to operate independently. They do operate independently in SSB, but not apparently in CW. Am I missing something? 73 de Roger, VK4YB __ 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] The K3 and the 630 meter band
In Australia we have a new band. The 630 meter band. It covers 472 to 478 KHz. They tell me there is a lot of interesting activity going on there. I tried to tune there with my K3 but alas it would only go down to 490 KHz. With RIT at -10 KHz and set to LSB, I could just start to hear signals at the top end of the band. How annoying! So close! but so far! Please Elecraft can you write us some software to extend coverage down to 472 KHz. Being able to transmit there would be even better! 73 Roger, VK4YB __ 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] P3 Spurii and a cure.
I have had 2 problems with my P3 Panadapter, both were the subject of comment on the Reflector. The first was spurii radiated from the P3 DC cord and picked by my nearby antenna on 144 MHz. This problem was largely solved by fitting a commercial RFI filter in the DC cord and ensuring that all panels were clear of paint in the corners where the connections are made. The second problem was the occurrence of wideband noise humps which drift across the display from time to time obliterating the genuine signals. I dubbed the characteristic doubled-humped noise signature as my noise monster. Experiment showed that these spurii and noise products were being generated in the P3 itself. It was not possible to precisely pin-point the source of these signals inside the P3 using a small pick-up loop. The signals were strong everywhere inside the P3 box, but, perhaps, were strongest near the processor chips. This would seem to make sense, but not everyone has these problems, so clearly the mechanism for producing this hash, varies from chip to chip. Thanks to everyone who responded. I am now able to report I have found a complete cure for these problems which works in my case, but, of course, I can not guarantee it will work in every similar case. The cure involves the use of conductive foam. This is the black foam that ICs are normally pushed into when they are delivered. It is carbon impregnated. You can tell the difference between this conductive foam and ordinary foam using an ohmmeter. Pressing the probes against the conductive foam will give a reading of a few Kohms. Ordinary foam will be open circuit. This foam is available from many electronic suppliers. I bought my foam from Farnell Electronics (Now called Element 14 in Australia), order code 168-7846. The cost is 89 cents for a sheet about the size of the P3 side panel. I cut the foam to form compartments to completely isolate the front panel, IF input board, and IO board. I even put foam between the folds of the ribbon cable. In doing this I was carefully not to allow the foam to actually touch any components or bare wires, otherwise a circuit would be formed. I cut the foam panels deliberately oversize vertically, so that when the lid was screwed down, ther e was pressure to make sure the foam had a conduction path to ground. The result of this work was that all spurii have disappeared and my noise monster has never shown its face again. My theory is that the foam is effective because it actually absorbs the RF signals and turns them harmlessly into minute amounts of heat. The problem with metal screening and chokes/capacitors is that these devices simply reflex the RF back. But back to where? The whole P3 box is already abuzz with these signals and they will try to get out anyway they can. The foam kills them dead. That's my theory anyway. If you have these or similar problems, give it a go. 73 Roger, VK4YB __ 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] P3 Double-humped Noise Monster
I am really happy I added the P3 to my K3. It is my window on the band. I can't imagine operating without it. I have had the P3 for six months now, but just recently it has started to display two big ugly humps of noise that drift across the display. This happens on all bands, but it might not appear for 20 minutes after switch-on. The double-humped noise monster is 30-40Khz wide and about -100 dBm level. When the antenna is disconnected the signals disappear but not the double-humped monster. There is no sound in the K3, so it looks like the noise monster is being generated within the P3. The frequency of the noise monster is incredibly sensitive to almost anything I do in the shack. It even shifts frequency if I put a few sheets of paper on top of the P3. If I put a book on top of the P3, the noise monster shifts completely off the screen (even with a 200KHz width). But it will drift back again later, whereupon I can remove the book and shift it again. This is a bit inconve nient, so can anybody tell me what is going on here? 73 Roger, VK4YB __ 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 Erratic SSB Power Output (G8DX)
I had a look at Jack's video showing the power fluctuations. They are quite rapid and continuous. If they stay like that, it will be a big help in tracking down the problem. The tx signal can be traced through the various stages with an oscilloscope to find where the steady signal begins the fluctuations. In my case, the darn fault would always disappear just when I was ready to start! However there are a few simple tests to do, before taking the covers off. Turn the power down to 12 watts or less. Do the fluctuations disappear? If so, problem is in the 100watt Amp. If not, 100watt Amp is eliminated. Are the fluctuations present at the transverter output? I have the 2meter transverter installed. So in my case, I only needed to look at the 2 meter output. If fluctuations are here, then the LPA board can be eliminated. There is also a method to look at the tx signal on the P3. It is described in the manual. Are the fluctuations present at this intermediate point? I do understand your frustration, Jack. There was a point when I was about to chuck my K3 in the trash. I'm glad I persevered and now I have a superb radio. 73 Roger, VK4YB __ 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 Erratic SSB Power Output
Jack, G8DX, wrote that his K3 has erratic output. I had the same fault on my kit-built K3 (ser # 6906) In fact my problem was worse, because at times I had no output and, occasionally, the K3 (set to 20w) would drive my Metron Linear Amp with 110w causing the breaker to trip. I followed the instructions from Elecraft support, and the problem improved, but it never went away completely. After 6 months the problem got much worse until output power failed completely. This was a blessing, because it was then easy to trace the fault. The fault was on the LPA board. Diode D1 was not soldered at both ends. Diode D1 is directly in the transmit path. It is a surface-mount device, and is not visible until the 100watt amplifier module is removed. Under the microscope, the contacts of this diode appeared slightly tarnished or dull. In a normal manufacturing process, each circuit board is fitted with a solder mask, and solder paste is wiped across the mask. This deposits exactly the right amount of solder paste on each solder pad. Then a Pick-and-Place machine places the components on the pads. Then, the loaded boards move slowly on a conveyor belt through a re-flow oven. All the connections are made perfectly. This process can occasionally go wrong. Because the contacts on D1 were slightly tarnished, the solder did not flow properly. The problem did not show up during testing at the factory because the contact was still touching the pad. Components come in batches, and if one diode has this problem, there may be other K3s out there with the same problem. If your K3 is showing this symptom, it might be a good idea to take a good look at the connections of D1 on the LPA board. After hand soldering the connections on D1, the output power from my K3 is now rock solid. 73, Roger, VK4YB __ 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] The K line. Is it the wrong way round?
I recently added the KPA500 to my K3 and P3. I put the KPA500 on the right of the P3 with the K3 on the left, just as is shown in all the K line adverts. This is the way it is intended. The rubber feet of the K3 and KPA500 touch the P3 and their carrying handles are on the outside. Also you will note that the mic and headphone jacks are on the extreme left where their cables will not get in the way of log books etc. This is all fine and dandy until I had to set the station up as a field portable. The position was cramped and the chair fixed. I had the P3 directly in front, but I had to reach to the left for all the important controls. I had the bright idea of switching the positions of the KPA500 and the K3. It was much better. My right hand fell naturally upon the tuning controls. When I got home I decided to keep the K line in the reverse order. I use the rear sockets for mic and phones, so there is no worry about leads crossing the operating desk. The handles of the KPA500 and K3 are now against the P3 case, but this makes little difference - See the photo of my station on QRZ.com. Hey, maybe Wayne and Eric are left-handers! 73 Roger, VK4YB __ 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] P3 generates noise on 144MHz
I fitted a commercial EMI filter (intended for 240V AC operation) inside my P3. It is a fully sealed unit with solder tags. This unit was connected in the + and - DC supply line. This filter completely removed any trace of noise from the power cord to the P3. I used a short coax with a one inch extension of the center wire to act as a "sniffer" to determine where the noise was coming from. This coax was connected to the K144XV input. Did this solve the problem? No! not entirely. I discovered there was now a small amount of noise being radiated from the RS232 lead and the IF input coax. These cables had been free of noise before. It seems to me that it is acting a bit like a boiling kettle - Block the spout and the steam comes out the holes in the lid! Why was there so much noise generation in the first place? I used my sniffer inside the P3 box to try and track down the precise source of the noise. But no luck. The noise was overwhelming everywhere at S9 + 20dB rising to S9 + 40dB near any of the ICs. This was on any frequency in the 2 meter band and beyond. At this point I re-visited the earthing between the panels that make up the P3 box. If you have been following this thread, you will know that I had previously cleaned all the mating surfaces. I looked again at the front panel. It is connected by four screws to the corner blocks. You can see where rectangles of masking tape have been placed to prevent the black paint from reaching the area which will mate with the corner blocks. The masking tape has not quite reached the edge of the board, leaving a one mm wide strip of paint right at both corner edges. It seemed very unlikely that this was preventing a good connection between the panels. Nevertheless I removed all trace of the paint in all four corners of both the front and back panels using a file and sharp knife. Did this have any effect? Well Yes! It reduced the noise by about 6dB. The noise which had started at S9 + 5dB was now down to about S3 which was the target value. The carriers at 19KHz spacing were just, but only just, perceptible with the 2 meter antenna connected. It would have been interesting to know what the noise would now be like without the EMI filter. Sorry guys (and gals), I did not do that experiment. When you have got something that works - leave it alone! I was also able to connect my other accessories to the switched 12V line from the K3 without affecting the noise. Another effect of my paint scraping exercise was that the position of the P3 was no longer critical. Before, if I pulled the P3 forward, the noise went down, but returned with the P3 in its correct position aligned with the K3. Roger Crofts, VK4YB __ 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] P3 generates noise on 144MHz
Last night I cleaned all mating metal surfaces in the P3 but, alas, this made no difference. The noise was still at S6. When I had the I/O printed circuit board out of the case, I noticed that the earth planes for the power supply section and RS232 section are separated by a zig zag gap. They are commoned together towards the inner edge. This has the effect of lengthening the route of RF currents from the earthy side of C500 to the metal case. My thoughts are that C500 will do a great job of removing RF differential mode voltages across the power cord. It will not do such a good job of removing common mode RF voltages from the power cord. I believe it is the common mode RF voltages that are the problem. This was confirmed when I replaced the power cord with a coaxial one (as suggested by John, G4ZTR). This made no difference to the noise. I found a ferrite ring which was large enough to pass the power plug through it. In fact I passed the plug through it three times to form two tight turns and I moved this choke as close as possible to the P3 power socket. The result was that the noise dropped to S4. Almost there! I think it would be better if the filter was totally inside the P3 case. I will try that next. Roger Crofts, VK4YB __ 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] P3 generates noise on 144 MHz
Thanks to everyone who responded. With your help, I have already reduced the noise level from S9+5db down to S6. The receiver noise floor is S3, so I still have a little way to go. There is now no doubt that the P3 power cord is responsible for most of the noise radiation. Putting the ferrite clamp-ons on the power cord as suggested by David, G4DMP, had the biggest effect. I also obtained a small improvement by removing some accessories that were sharing the 12V switched output from the K3. I am using the power cord supplied with the P3, but I had a splitter at the K3 end to feed power to a keyer and pre-amp. The extra cables for these devices were acting as additional antenna wires to radiate the 144MHz noise. However it seems to me that the noise should not be getting onto the P3 power cable in the first place. I looked at the P3 circuit diagram and was surprised to see that there is no series inductor in the power lead as it enters the box. Every other DC (or AF) connectio n I could find in the K3/P3 was protected by a series inductor and usually multiple bypass capacitors. There is a single bypass capacitor in the P3 power line. It is C500 with a value of 100nF. It seems to me that the effectiveness of this bypass capacitor very much depends upon a very good and direct connection between the I/O board printed circuit and the case. This connection relies on the 4 screws associated with the two 9pin D connectors. On re-reading the construction manual, I notice there is an instruction at the top of page 41, to check the surface of the metal work which mates with these connectors. At the time of construction I only gave this a cursory glance. I may have been remiss here. I will polish this surface with emery cloth and see if it makes any difference. I also tried powering the P3 from another 12Volt power supply, but the noise remained at S6. If I stretched the power cord in a certain direction the noise could be made to drop to the receiver noise floor (S3). I guess that this is because the power cord "antenna" has a null towards my 2 meter antenna in this particular arrangement. This is a solution, but not a very good one! I will continue my experiments and let you know how they go. Roger Crofts, VK4YB __ 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] P3 generates noise on 144 MHz
I recently installed the K144XV 2meter converter in my K3. I could work strong stations on 2m with no problem, but weak stations were swamped by noise which was S9 over the entire band. My P3 was showing that the noise consisted of carriers every 19KHz with lots of buzzy noise in-between. I soon found the source of the noise. It was the P3 ! When I turned the P3 power off, the noise completely disappeared. With the P3 on and the antenna replaced with a dummy load, the noise also all but disappeared. When I removed the RS232 cable and the IF cable from the P3, leaving only the power cable, the noise persisted at the same strength. So it appears that the P3 box is radiating this noise directly into my antenna. My antenna is a 2meter ground plane on the roof of my shack. It is about 8 feet from the P3. Obviously a solution would be to move my 2 meter antenna well away from the shack. I was not able to find any mention of this problem in the archives. Is there something wrong wi th my particular P3 or do they all do this? Roger Crofts, VK4YB __ 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
