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I'm just starting to build my Sea Sprinte from the March 2023 Buildathon in which we lost Spectrum Internet during the Build sessions and I also had blown out my ACL then. I am deciding to eliminate the Receiver section since I have a better Icom communication receiver I use with my Tuna Helper T/R switching. Some were reporting ~500-600mw of power via the full-blown version. I am also eliminating the NoTune Antenna Coupler so I can use my 49:1 EFHW. I know it is capable of putting out slightly more power than a half-watt so I am going to ask if anyone has any ideas on the best way to boost that to 700-800mw or so. Since the 10K ohm emitter bias resistor on the 2N3866 is grounded during transmit, there is little resistor to change it. There is less reason IMHO to messing with any of the base voltage dividers as that could cause instability of the Oscillator circuit, however I can play with that when I get that far. I am going to keep it running up in the old Novice band (7.110MHz) portion as I do see some POTA activators up there from time to time and portions of that section are mostly free of FT8 activity except mainly for contesting. Cheers, Davey - KU9L

Just upgrading the transistor Q2 from the stock PN2222A to 2N3866 (metal) with the heatsink borrowed from my Super Tuna Kit has yielded an increase in output power from 275mw to 355mw, relatively speaking, without touching the 56-ohm emitter bias resistor. There is slightly more gain in the upgraded part number. We were cautioned in the Buildathon not to reduce the 56-ohm resistor to zero without close monitoring of the temperature of the transistor. I bought a whole variety assortment of trim pots and have clipped off one leg to install it in place of the stock R7. It measures a minimum of 2.2 ohms to ~113 ohms, so it should yield good results in obtaining that near 700mw goal. I do have a couple of versions of the Tuna Topper, so controlling the input power to the final amp would make it a useful feature. Davey - KU9L

When considering moving your 40th Anniversary TT2 to a new band, do not forget to follow the IN to OUT path when choosing component values from a chart. The 40th Anniversary TT2 Schematic is laid out real nice, but when looking at the Band Pass filter notice that it is printed Right to Left for the IN to OUT path. When you are looking at a filter chart (E.G. https://www.qrpme.com/docs/SPT-Schematic3.pdf) in addition to having to keep the new part identifier in mind, you also have to consider it will present those Band Pass values in a Left to Right manner. This way you will spend less time standing on your head with the RF Probe wondering just what the meter is showing. Maybe this fact is obvious to some, however, I am the most Dyslexic person on the planet, LOL. Happy experimenting ... Cheers, Davey --KU9L

Super Tuna assembly is now essentially complete and I am entering the tweaking and troubleshooting stage. I built the 30M Band Module first do to that band being more open during daylight hours in the winter, especially when picnic table operation early morning or at dinner time involves dealing with herds of the Florida state bird flocks that carry you away unless you are walking at battlespeed. - Initial power-up revealed the Red LED cycled perfectly during straight key closes. Good, the keying circuit is working. - Tuning in on my receiver on the table, I found the signal at 10.11454 MHz with the VXO turned to the extreme left limit. I am using a 10.116 MHz crystal. - Turning the VXO to the extreme right limit, the signal moved to 10.14655 MHz. That is a nice 3 KHz range and the XVO tunes as smooth and as linear as a VFO. - In my book, this meant transformer T1 Primary was connected and functioning with the oscillator doing exactly what it should be doing. The waveform sounded crisp and stable with a high chance the component values were correct and soldered correctly. - I then installed the final Q3 transistor into its socket and added its heatsink. The sound in the receiver did not change, but the RF Probe circuit does not register a voltage, the final amplifier Q3 isn't switching perhaps. I traced the circuit back from the RF Probe (Peak-n-Hold circuit) to the collector of Q3 and everything appears to be correct, including the bandpass filter (which has no immediate bearing on Q3 turning on). At this point I verified the Transformer T1 again, the windings are correct, 25T Primary & 5T Secondary. My T1 is 90 deg turned from the instructions due to the direction I wound the first turn, but all subsequent turns followed the same pattern to use as minimal wire as possible and no soldered wires crossing each other. Primary & Secondary wires are soldered in the correct solder pads. - Next step: I added solder tinning to the transistor legs as they fit too loose in the 3 pins for my comfort. I tried several 2N3866 transistors with no change in action. Zener ZD1 is the correct part as well as all resistors and caps. I wondered if adding solder to the legs to tin the transistor legs risked ESD failure. I have not yet replaced the 3-pins soldered into the board that forms a socket, I have nothing in the junk box that will work better. - Later today I will take more measurements with the RF Probe to gain some more data for comparison. Notes: There are two Q3 transistors on the schematic, the one in the Keying Circuit is actually Q4. The R10 on the schematic current limiting the Red LED is actually R11 and R10 is assigned to be a current limiting resistor for the optional LED that would iluminate the PWR and FUN trim pots (LED not installed here). If measured voltages at the Base of Q3 are insufficient to turn it on, I will try rewinding although the form looks very ideal. Winding it for T1 to be turned 90 deg should not affect BE Voltage measurements in any way. If BE Voltage measurements are good, I may try lifting ZD1 as it could be clamping too low although it does not show as being shorted either. Back to the fun after a walk with the wife ... Davey - KU9L

I am just starting to build my SKK CW Keyer module and noticed there is only a schematic on the listing as there was never a Buildier's Guide created. Are there any special considerations to watch for in the building sequence? Although similar but different, I have printed the PicoKeyer Module Builder's Guide to aid in my assembly efforts. I combed over all of my old kits and did not find a PicoKeyer Module, one of the few I never obtained. I bought quite a few QRPme kits in the middle of the last decade but was stricken by sudden cataracts that temporarily ended my newly revamped Ham Career, especially my soldering. It took over three years to get my cataract surgeries as we had no health coverage and by then all my QRPme kits were replaced by 2-3 newer versions, however, I do build some of the older ones yet today and also enjoy mining them for parts when needed! I have not fired up my newly built Super Tuna yet, but am working toward trying to connect with Aaaron W4ARB, who does 30M POTA activations from Tuskegee NF 2-3 days per week from Eastern AL which is about 475 miles from where I am here near Winter Haven, FL. 10.116 MHz is where we try to connect mornings. A 2-3 hour POTA session was too much for my 62-year-old straight key fist when I had a 20-year absence from keying. Even my big buck German keyer with magnetic bearings can be a bit much for my wrists and my two Pennteck 5W QRP rigs allow two message memories that save my bacon as I try to stretch from 14 wpm to 22 wpm again. I QRS when POTA Activating near 7.110-7.122 MHz, but my sending limitation is my bottleneck over my ability to "contest" at reasonable speeds. When I was 15 years old a retired Railroad guy named Rusty showed me he could send or copy 35 wpm simultaneously while holding a conversation with me, and he was in a wheelchair. His Keyer was a bug, but he also had a Keyer full of vacuum tubes that had a wonderful sound. Two years later when I got my Novice ticket I found out that he had passed away, the world hasn't been the same since. So the SKK Keyer for my Super Tuna ][+ is going to save my bacon, half the trick is not to use my manual tools the day before so my wrist feels more like a spring chicken ... Cheers, Davey --KU9L

The original Tuna Helper T/R switch says it is compatible with TT2, but is it compatible with Super Tuna ][+ 2-W levels? I swear I remember reading that it could do 1-W but my eyes couldn't find that again no matter where I looked. The newest version with the larger can & circuit board does say it is Super Tuna ][+ compatible, but again the exact data escapes my eyes. I might build another T/R Switch of the newest layout. It has an RF Probe built into it with the Peak-n-Hold circuit that is great for checking how much power is being generated. I want to ohm out the bare board as I go along like I used to do when I would build my "Golden" boards to use against the Test Equipment I built so I could release my software for production to run a batch of boards & the Union Test Operators to troubleshoot for found assembly errors. Anyway, if someone has the newest layout that they haven't built yet and are interested in parting with it, give me a private email. In the meantime I am going to finish winding toroids for my Super Tuna ][+ that I assembled last summer before I got too busy having fun activating 4 parks for POTA about a dozen times QRP. I had to get out on my days off or I would get roped into working. Soldering and POTA offer equal enthusiasm to me so an activation using the Super Tuna at ~2-Watts would be ducky x2. Cheers, Davey - KU9L

Window screen antenna ground network- I can't believe what this does! #hamradioqa Window screen antenna ground network- I can't believe what this does! #... This was my original inspiration to try it on my own, but Michael has multiple videos on this subject. Michael builds and designs antennas for a living, but part of the fun is test, test, test in the real world. Yes, most of us do POTA on 40-17 meters. If I ever do 80M it isn't with a vertical since I do quick deploys and takedowns. Often my state parks campsites don't have the room for an 80M antenna 1/2~ wire. Okay, back to QRP building ... On Tuesday, January 16, 2024 at 07:05:53 PM EST, David Knapp via groups.io <renewables@...> wrote: Oh, I agree 100% David & over 30 years got a belly full of creating such documentation in aerospace. There is a time and place for it indeed which is what I will put into the QRPer.com article I am writing. I just know that instead of fighting with the antenna analyzer, additional ground stakes for the 2-3 counterpoises, and tune/check/tune/check/tune/check cycles endlessly I am now up and running in 5 minutes and have doubled the number of log entries into my activations for that quick hour I get before I have to muster up my two maintenance men to start handing out weedeaters, chainsaw, TP (camp host supplies), and generator fuel as they head out to the campgrounds. That hour I can spend playing radio more than compensates for the 12+ hour days we spend daily running our assigned 13 USFS campgrounds over a 65-mile-wide valley, w/lakes, and day-use areas. I had planned to play radio all day, but post medical bills & drained 401K we get to diversify our daily activities, Cheers, Davey --KU9L On Tuesday, January 16, 2024 at 04:11:44 PM EST, David Ryeburn <a3a05603@...> wrote: On 2024-01-16 12:13 p.m., David Knapp via groups.io wrote: > For those hating to install radials for a counterpoise to their portable vertical or EFHW antenna, I have had good luck throwing two 48"x 84" aluminum window screens on the ground connected via two alligator jumpers. I am also testing a version that uses a Faraday cloth of similar dimensions, easier to fold into a bag and throw out quickly for a POTA activation. Since I hate to use more than one or two counterpoise radials during an activation, I was pleasantly surprised that the aluminum screens presented a much better VSWR bandwidth than 2 radials, depending on the ground conductivity. SWR isn't everything. Antenna + ground system efficiency is more important than SWR. You should measure the RESISTIVE component of your antenna + counterpoise (or window screen) system, not just the SWR, with each ground return system. (Reactance can be tuned out with whatever antenna coupler you may be using.) An antenna analyzer will do this measurement properly. Suppose the antenna plus radial wire combination measures a lot less than R = 50, and I suspect it will, with a short antenna. (To a first approximation, the radiation resistance of a short monopole is proportional to the square of its length, and it doesn't get up to 36 ohms or so until the length is a quarter wave.) And suppose the resistance using a window screen measures closer to 50 ohms. The window screen is going to give a better SWR. And the difference in resistances is made up of ground losses, so your distant signal is going to be a lot weaker with the window screen (provided your antenna coupling scheme will tolerate the lower input impedance with the radials). Another way to find out what is going on: have a friend measure your signal strength, both ways. This should be done at a good distance, a number of wavelengths away from the antenna so as to be out of the near field, perhaps a few blocks away, but close enough that you are looking at the ground wave to avoid normal ionospheric variation. Maybe the window screen will do a good job up on 10 m, but at lower frequencies I'll bet longer radials will win (unless your ground conductivity is very high, as in a salt marsh). David VE7EZM and AF7BZ

Oh, I agree 100% David & over 30 years got a belly full of creating such documentation in aerospace. There is a time and place for it indeed which is what I will put into the QRPer.com article I am writing. I just know that instead of fighting with the antenna analyzer, additional ground stakes for the 2-3 counterpoises, and tune/check/tune/check/tune/check cycles endlessly I am now up and running in 5 minutes and have doubled the number of log entries into my activations for that quick hour I get before I have to muster up my two maintenance men to start handing out weedeaters, chainsaw, TP (camp host supplies), and generator fuel as they head out to the campgrounds. That hour I can spend playing radio more than compensates for the 12+ hour days we spend daily running our assigned 13 USFS campgrounds over a 65-mile-wide valley, w/lakes, and day-use areas. I had planned to play radio all day, but post medical bills & drained 401K we get to diversify our daily activities, Cheers, Davey --KU9L On Tuesday, January 16, 2024 at 04:11:44 PM EST, David Ryeburn <a3a05603@...> wrote: On 2024-01-16 12:13 p.m., David Knapp via groups.io wrote: > For those hating to install radials for a counterpoise to their portable vertical or EFHW antenna, I have had good luck throwing two 48"x 84" aluminum window screens on the ground connected via two alligator jumpers. I am also testing a version that uses a Faraday cloth of similar dimensions, easier to fold into a bag and throw out quickly for a POTA activation. Since I hate to use more than one or two counterpoise radials during an activation, I was pleasantly surprised that the aluminum screens presented a much better VSWR bandwidth than 2 radials, depending on the ground conductivity. SWR isn't everything. Antenna + ground system efficiency is more important than SWR. You should measure the RESISTIVE component of your antenna + counterpoise (or window screen) system, not just the SWR, with each ground return system. (Reactance can be tuned out with whatever antenna coupler you may be using.) An antenna analyzer will do this measurement properly. Suppose the antenna plus radial wire combination measures a lot less than R = 50, and I suspect it will, with a short antenna. (To a first approximation, the radiation resistance of a short monopole is proportional to the square of its length, and it doesn't get up to 36 ohms or so until the length is a quarter wave.) And suppose the resistance using a window screen measures closer to 50 ohms. The window screen is going to give a better SWR. And the difference in resistances is made up of ground losses, so your distant signal is going to be a lot weaker with the window screen (provided your antenna coupling scheme will tolerate the lower input impedance with the radials). Another way to find out what is going on: have a friend measure your signal strength, both ways. This should be done at a good distance, a number of wavelengths away from the antenna so as to be out of the near field, perhaps a few blocks away, but close enough that you are looking at the ground wave to avoid normal ionospheric variation. Maybe the window screen will do a good job up on 10 m, but at lower frequencies I'll bet longer radials will win (unless your ground conductivity is very high, as in a salt marsh). David VE7EZM and AF7BZ

From a Rockmite newbie, does the current version of the Rockmite ][ - 10M come with the RM][-10 v3 PwrEff Mod ? I would say no, but after a good 10-minute search, the RM][-10 v3 PwrEff Mod is the only PwrEff Mod that doesn't show up in the side menu as the 80-15M versions do. I thought I'd ask the question before I asked about which enclosure and keyer chip was available and/or recommended, etc. A one-button to-order all of the above would be nice as well, but I won't keep over-taxing my welcome. ;-) For those hating to install radials for a counterpoise to their portable vertical or EFHW antenna, I have had good luck throwing two 48"x 84" aluminum window screens on the ground connected via two alligator jumpers. I am also testing a version that uses a Faraday cloth of similar dimensions, easier to fold into a bag and throw out quickly for a POTA activation. Since I hate to use more than one or two counterpoise radials during an activation, I was pleasantly surprised that the aluminum screens presented a much better VSWR bandwidth than 2 radials, depending on the ground conductivity. Another limitation is that the antenna feed-point is best within 17" of the ground surface, but more testing is needed. Happy to comply, when I can. I am testing a new cloud-based video editing software so I do not have to use the clunky MindMovies software anymore. Looking forward to playing more radio ... Cheers, Davey - KU9L

Gangue, QRPme 2024 LIVE Stream Buildathon #1 W1REX & friends will be hosting a LIVE streamed BUILDATHON...over 3 nights....starting at the end of January. Sunday January 28, Wednesday January 31 and the following Sunday February 4 are the nights scheduled for the 3 sessions centered around building a Tuna Tin 2 40th Anniversary kit. In previous LIVE streamed BUILDATHONS, we have been limited in trying to cram an entire BUILDATHON in a 2 or 3 hour time slot. The builds were done in a rather quick pace in order to get everything into the single session with not much time for in depth discussion on the what and why. This BUILDATHON will be much different. Each session will focus on a different aspect of the process. Sunday January 28 5PM EST Objectives: WHY QRP, TT2 circuit operation, parts identification & sorting, soldering techniques and practice. We will be talking about all the above stuff then ending with soldering practice building a couple of elementary pieces of QRP test equipment useful after your successful completion of the 40th Anniversary Tuna Tin 2 kit. Lots of time to cover these topics with Q&A encouraged. Additions to the 40th Anniversary kit will include parts & pcb for a simple straight key, dummy load and RF Probe. These 3 items are much simpler than the actual TT2 transmitter so easier to build. They will make good starting points for those learning to solder YET very useful when checking out your completed Tuna Tin 2 transmitter. Wednesday January 31 8PM EST Objectives: BUILDING a QRP kit! Since you now know 'everything' about the Tuna Tin 2 design and how to solder, we get to work and actually BUILD the kit. With 37 total parts, this TT2 kit is a relatively simple to build and should be able to be completed in one evening. We will take it slow and since this session is not in another event's time window, we should be able to take it slowly so that everyone should be able to keep up....now that you are ALL experienced solderers.... Sunday February 4 5PM EST Objectives: Getting everyone's kit up & running and testing its performance. We will have the whole session devoted to getting EVERYONE's kit completed and running as expected. We will learn how to use the key, dummy load and RF Probe to debug and check transmitter performance. We will be LIVE streaming this BUILDATHON from Stephen, N1SH, Houser's QTH and will have plenty of time each evening to get through the objectives. It will be broadcast on my YouTube account (Rex Harper) and on Charlie “Red” Brown, NJ7V, (Red Summit RF) Podcast channel. All 3 sessions will be archived on those sites immediately after their broadcast so latecomers will be able to review any missed material.... Times will be 4PM EST on the Sunday sessions and 8PM EST on the Wednesday session. All kits will be shipped via USPS Priority Mail so US and Canada orders should have ample time to arrive on time. DX orders are a little iffy unless they are ordered ASAP. Stay tuned to this product page for more information as I will be posting lots of pre-Buildathon information before the 1st session. Website: http://qrpme.com/ Buildathn page:http://qrpme.com/?p=product&id=LS1 Hope to see you there! Rex W1REX

Hello, folks! Just seeing if anybody was up to much this summer. I've started and stopped on a few projects. I was hoping after I graduated in April (MS), I'd have more time, but it hasn't been that way. Now it's back to school again in a couple of weeks, so who knows what projects the future holds! Anybody want got anything cool going on? -HRS H. Russell Smith, N0QLT

I am getting ready to build a pile of Tunas, acquired from QRPme directly and through estate sales, all unbuilt. The first is a retired single band Two Tinned Tunas, now replaced by the EZ Build Version. The 2nd is an original Super Tuna ][ with version not marked, it has the scoring in case you want to put it in a square tin can. Third is a Super Tuna ][+ marked Ver 2. The Fourth is a Super Tuna ][+ marked Ver 4. I have a generous supply of band modules from the last three that might even allow me to have at least 2 xtals per the four bands, 10M included. First, I have 32 separate water tests for CL2 and Nitrates to sample over the next couple of weeks, pumping out all of the iron and other exotic minerals cruising around the mountain cracks in the hand pump wells. It has been raining like cats and dogs day and night here in the central Colorado mountains, so there are no fire bans this month, but the problem is the skidders are snowed in without being able to get a lot of the logs out that would be sending 1096 bundles of firewood to us x 4 or 5 depending on how wet of a summer it is. I will have photos of the 3-band vertical I am building as well as some graphs of the VSWR patterns so the "Little Super Tuna ][+ that could" will be heard outside of the valley surrounded by 14K' peaks on all four sides. Cheers, Davey - KU9L