qrper.com/2023/12/ssb-and-cw-qrp-pota-testing-my-new-km4cft-end-fed-antenna-kit/?swcfpc=1 Click the link above to read full details about this activation, including all equipment links, at QRPer.com.
Wow, that antenna works extremely well! I'm super happy you are enjoying the antenna. Fun fact for anyone who gets this antenna kit. The unit that Tom is using is the same one that is shown in the assembly manual (aka its the one I built to make the photos in the guide) I think i should build myself an EFHW with a 30 and 40 meter link like you did. Curious what lengths you used too. 72 DE Jonathan, KM4CFT
So I never properly measured before I trimmed. I think for the 30M band, I started with 55'. Trimmed off quite a bit. Then added 18' or so, then trimmed it down. I would have to measure it properly to give you a good idea.
I finally made it to one of your videos! I remember your signal had faded out for a second when you came back to me, thanks for persisting and slowing down so much for my 12wpm - KB6R
Nice, Thomas! I don't think I've ever done a cross-mode contact. I have done HF satellite QSOs cross-band, 10m & 15m, I believe, maybe RS-10/11, somewhere along in the mid/late '80s? One request which may not be important enough for you to do, but I know maybe 2 knots. Would you consider doing a very short, 5-10 min video, on that subject as well as cord types, etc.? And it's pretty easy to slow down or repeat stuff on CZcams, so if we can see it all, only 1 or 2 show-and-tells would work well. TU, de KA8VLW, Ken, Michigan
I'll give this some thought. Thing is, there are SO many great videos out there about typing various knots. I'm not sure I could do it justice. I might try, though.
@@ThomasK4SWL You're probably right, but if I don't even know the name of the knot, I'm not sure how to find it. If you do tackle this request, one thing you might hit would be joining widely different sizes, like parachute cord and fishing line. I know there have to be special ways to do that. Thanks either way, I will still watch and enjoy your videos! If all you do is name the knots and try showing them without having hands/fingers in the way, that would go a long way.
@@kendebusk2540 I just remembered...there's an excellent article with videos on Michael (KB9VBR)'s website: www.jpole-antenna.com/2014/06/18/knots-for-antennas-and-support-structures/ It shows all of the knots I tend to use for radio. Micheal has an excellent channel and I'd encourage everyone to subscribe. I'll still make a note to show knots at some point.
I love the ultra-focus on small size, but a version sized for slightly more power (like G90 20W) would be convenient so you can use the same antenna for a G90 as the MTR3b. I don't think the bigger toriod would add that much. Probably good with a 16mm.
I would have to say your audio is so good at the table it’s not needed. Where it could aid you is to wear it while putting up the antenna to talk everyone through it in perfect audio. On my channel I need to keep my Go Pros waterproof so I cannot add the media mod too easily and use the DJI mics… so I always have to play attention to my audio. Again your audio is perfect at the table. Sometime could you take a picture of how close you have your camera set up off your right shoulder? I have e the same tripod … thx. Bob
I'm a bit surprised the wire cut for 30 m had such a low SWR on 17 m. The higher frequency band is nowhere near twice the frequency of the lower one. If you assume 5% shortening (end effect at both ends), a half wave at the 10.125 MHz centre of the 30 m band would be about 467.4/10.125 = 46.16 ft long. If instead you only assume 2.5% shortening (end effect at the 49:1 transformer end, no end effect at the far end) then you get 479.7/10.125 = 47.38 ft. Just how long is your 30 m antenna section? On 17 m we want a full wave antenna so our numerator should be 467.4 + 492 = 959.4 or else 479.7 + 492 = 971.7 ft depending upon whether end effect occurs at both ends or only at the transformer end (the 492 rather than a second smaller number is because there is no end effect at the middle of a full wave long piece of wire). So I'd expect resonance at either 959.4/46.16 = 20.78 MHz or at 971.7/47.38 = 20.51 MHz, Either way, that's a lot closer to the low end of the 15 m band than to the 17 m band. So just what were your lengths? You might run an SWR curve over a wide range of frequencies. If the thing is very broad-band, then suspect serious losses somewhere. In the transformer? Or were you using an external antenna tuner (the TX-500 doesn't have one)? David VE7EZM and AF7BZ
Both times I've build a 30M EFHW, they were acceptably resonant on 17M. This one is the best yet. I was not using an ATU--the antenna was directly connected to the TX-500. Sometimes, there's just a difference between theory and practice. I'll see if I can measure the antenna sometime.
This was wire from my friend Alan. A large spool he found at a hamfest. tHe company no longer exists (since the late 80s). It's a stranded 26AWG wire with a nice, slick jacket.
Yep. I sure could. IN fact, the best way (in my opinion) to do SSB activations is using a boom headset and having the radio in VOX mode. It completely frees up your hands to log.
So many people say, “You can’t get a good SWR on an EFHW without a counterpoise!” I know you didn’t use one, but you did have a good length of coax that likely acted as a counterpoise. Any chance you might connect that antenna directly to the radio and see what results you achieve? Also, you can never have too much battery.😂
I may give that a go. I'll need a male/male BNC adapter, though. I don't have one of those. Also, I'm not sure I've ever added a separate counterpoise wire to an EFHW. I just let the cable shield do the work. I do have an attachment on this antenna for a dedicated counterpoise, though.
I typically use an EFHW with no counterpoise while QRP. My antennas attach directly to the radio. The radio chassis capacitively couples to me, and I become the counterpoise. If you watch a few of my videos, you'll see that it's clearly ineffective 😉. Is it more efficient with good ground coupling? Probably a little. Is it worth the hassle? Not for me. Also, that winder in one I designed and is available on Printables as an STL for free.
qrper.com/2023/12/ssb-and-cw-qrp-pota-testing-my-new-km4cft-end-fed-antenna-kit/?swcfpc=1
Click the link above to read full details about this activation, including all equipment links, at QRPer.com.
That CW contact had me in tears. Dit Dit.🤣
A little SSB isn’t going to stop a CW man! Loved the cross-mode QSO!
Agree with the others. Loved the vocalizing 'dit dit' at the end of the cross-mode contacts. Classic.
Actual lol at the sudden cross mode CW. “Dit dit.” 29:06
Besides his amateur radio content, Alan W2AEW has some of CZcamss best electronics tutorials on his channel.
100% Agree!
Alan is great! The electronics professor I never had...
Wow, that antenna works extremely well! I'm super happy you are enjoying the antenna. Fun fact for anyone who gets this antenna kit. The unit that Tom is using is the same one that is shown in the assembly manual (aka its the one I built to make the photos in the guide)
I think i should build myself an EFHW with a 30 and 40 meter link like you did. Curious what lengths you used too.
72 DE Jonathan, KM4CFT
So I never properly measured before I trimmed. I think for the 30M band, I started with 55'. Trimmed off quite a bit. Then added 18' or so, then trimmed it down. I would have to measure it properly to give you a good idea.
Thanks for doing SSB
So glad that the wire worked out so well for you. Now I need to build a 40/30m linked EFHW myself
It's brilliant stuff, Alan!
What was the wire Alan? Teflon coated?
@@cthoadmin7458 either Teflon or something similar. Tough but flexible, and slick (not sticky).
That cross mode contact…. HILARIOUS!!! And the dit dit at the end, I’m dying! LOL
Holy cow a video of you doing SSB?! I feel like thats unheard of! haha. Thanks for all the great videos.
😆
I was so HAPPY to get you on SSB! Been waiting for this video. Please do SSB a little more often. 73 Michael
Great to work you, OM! I do plan to implement more SSB this upcoming year.
That radio announcer voice doesn’t hurt you one bit either. 73’s de n5vwn dit dit
Wow SSB, very nice!! That rig has some nice quiet recieve audio, I'm impressed, thank for posting this video my friend!!!!
Okay that cross mode was great! Unfortunately I would have a clue as I have only learned CQ and my call🤦♂️
Give it time and you'll start to pick up CW. Just takes a lof of listening time. :) You've got this!
I finally made it to one of your videos! I remember your signal had faded out for a second when you came back to me, thanks for persisting and slowing down so much for my 12wpm - KB6R
You did great!
Great video as always. I lost it when you said "dit dit" hahaha. 73 K3KLB
😁
nice to get in the SSB log
Nice, Thomas! I don't think I've ever done a cross-mode contact. I have done HF satellite QSOs cross-band, 10m & 15m, I believe, maybe RS-10/11, somewhere along in the mid/late '80s?
One request which may not be important enough for you to do, but I know maybe 2 knots. Would you consider doing a very short, 5-10 min video, on that subject as well as cord types, etc.? And it's pretty easy to slow down or repeat stuff on CZcams, so if we can see it all, only 1 or 2 show-and-tells would work well.
TU, de KA8VLW, Ken, Michigan
I'll give this some thought. Thing is, there are SO many great videos out there about typing various knots. I'm not sure I could do it justice. I might try, though.
@@ThomasK4SWL You're probably right, but if I don't even know the name of the knot, I'm not sure how to find it. If you do tackle this request, one thing you might hit would be joining widely different sizes, like parachute cord and fishing line. I know there have to be special ways to do that. Thanks either way, I will still watch and enjoy your videos! If all you do is name the knots and try showing them without having hands/fingers in the way, that would go a long way.
@@kendebusk2540 I just remembered...there's an excellent article with videos on Michael (KB9VBR)'s website: www.jpole-antenna.com/2014/06/18/knots-for-antennas-and-support-structures/
It shows all of the knots I tend to use for radio. Micheal has an excellent channel and I'd encourage everyone to subscribe.
I'll still make a note to show knots at some point.
@@ThomasK4SWL Very nice, thanks! I do watch his channel but that may have posted before I started. I will watch :)
I love the ultra-focus on small size, but a version sized for slightly more power (like G90 20W) would be convenient so you can use the same antenna for a G90 as the MTR3b. I don't think the bigger toriod would add that much. Probably good with a 16mm.
You make me want to learn CW! 73 de VK4QP
Do you use a DJI mic with your DJI camera or is the camera just picking your voice up? Enjoyed the SSB activation!
Just the camera. That said, I bought the wireless mic system for mu OSMO 4 and will be using it soon.
I would have to say your audio is so good at the table it’s not needed. Where it could aid you is to wear it while putting up the antenna to talk everyone through it in perfect audio. On my channel I need to keep my Go Pros waterproof so I cannot add the media mod too easily and use the DJI mics… so I always have to play attention to my audio. Again your audio is perfect at the table. Sometime could you take a picture of how close you have your camera set up off your right shoulder? I have e the same tripod … thx. Bob
I'm a bit surprised the wire cut for 30 m had such a low SWR on 17 m. The higher frequency band is nowhere near twice the frequency of the lower one. If you assume 5% shortening (end effect at both ends), a half wave at the 10.125 MHz centre of the 30 m band would be about 467.4/10.125 = 46.16 ft long. If instead you only assume 2.5% shortening (end effect at the 49:1 transformer end, no end effect at the far end) then you get 479.7/10.125 = 47.38 ft. Just how long is your 30 m antenna section?
On 17 m we want a full wave antenna so our numerator should be 467.4 + 492 = 959.4 or else 479.7 + 492 = 971.7 ft depending upon whether end effect occurs at both ends or only at the transformer end (the 492 rather than a second smaller number is because there is no end effect at the middle of a full wave long piece of wire). So I'd expect resonance at either 959.4/46.16 = 20.78 MHz or at 971.7/47.38 = 20.51 MHz, Either way, that's a lot closer to the low end of the 15 m band than to the 17 m band.
So just what were your lengths? You might run an SWR curve over a wide range of frequencies. If the thing is very broad-band, then suspect serious losses somewhere. In the transformer?
Or were you using an external antenna tuner (the TX-500 doesn't have one)?
David VE7EZM and AF7BZ
Both times I've build a 30M EFHW, they were acceptably resonant on 17M. This one is the best yet. I was not using an ATU--the antenna was directly connected to the TX-500.
Sometimes, there's just a difference between theory and practice.
I'll see if I can measure the antenna sometime.
Great video as usual and the SSB was a nice twist. Can you tell me what kind/size wire and brand? Or where to buy?
This was wire from my friend Alan. A large spool he found at a hamfest. tHe company no longer exists (since the late 80s). It's a stranded 26AWG wire with a nice, slick jacket.
I wonder if you could use a foot pedal microphone while you do SSB. It would free up a hand.
Yep. I sure could. IN fact, the best way (in my opinion) to do SSB activations is using a boom headset and having the radio in VOX mode. It completely frees up your hands to log.
@@ThomasK4SWL I didn’t even know that existed…
Thomas, I was looking for the details of the case, do you have it handy? Thanks in advance, Terry de K1TDG
Thank you for reminding me! It's this one: amzn.to/3RBWInM (affiliate link)
@@ThomasK4SWL thank you, I have that ordered now, I hope you get a couple of shekels in the process.
So many people say, “You can’t get a good SWR on an EFHW without a counterpoise!” I know you didn’t use one, but you did have a good length of coax that likely acted as a counterpoise. Any chance you might connect that antenna directly to the radio and see what results you achieve? Also, you can never have too much battery.😂
I always found that statement funny because I've built plenty of EFHW antennas and I never use a counterpoise. I just let my coax take on the role.
I may give that a go. I'll need a male/male BNC adapter, though. I don't have one of those. Also, I'm not sure I've ever added a separate counterpoise wire to an EFHW. I just let the cable shield do the work. I do have an attachment on this antenna for a dedicated counterpoise, though.
I typically use an EFHW with no counterpoise while QRP. My antennas attach directly to the radio. The radio chassis capacitively couples to me, and I become the counterpoise. If you watch a few of my videos, you'll see that it's clearly ineffective 😉.
Is it more efficient with good ground coupling? Probably a little. Is it worth the hassle? Not for me.
Also, that winder in one I designed and is available on Printables as an STL for free.