David, you are the Mr. Rodgers of Amateur Radio! Your grounded, soft-spoken ham radio episodes are very comforting during this COVID-19 crisis. I"ve subscribed and have been watching your videos for weeks, but wanted you to know how much you are appreciated. Keep up the great work! Thanks 73s Greg, KJ6ER
Thanks for this tip, Dave! I used this method on an MJF-17754 Dipole I recently purchased from DXEngineering. Also, I watched your video, "The MFJ-17754 40/20 Trapped Dipole (#265)", which I'm glad I did because I didn't realize it was shipped with excess wire on both ends. I'm new to HF, but I do have a mobile 2M unit in my Jeep & an HT. I got my Tech two years ago, but decide to jump into the HF area with a Yaesu FT-450D. Due to my HOA, I'm installing my dipole in the attic area. I have a 2-story home, facing south, so I have adequate space in the attic. I'm watching a lot of your videos to educate myself on everything Ham Radio!
I wish I had seen this a year ago when I had to cut off the end of a ZS6BKW because it was finished with a heavy duty ferrule permanently crimped on. I couldn't cut through the ferrule to undo it so I had to cut the looped end and insulator off from the antenna. Like your store bought antennas, mine was too long and it resonated below all ham bands. All together I cut off 6 inches, and folded back six more inches after replacing the insulator, making it over a foot shorter at each end to resonate close to the middle of the bands. In all fairness It's not at least 40' in the air as recommended, but rather 27', naturally making it perform as though it's too long. This is a really good antenna trimming tip. Thanks Dave.
This is exactly the sort of detail that most skip over. An integral part of the electronics and engineering which form part of the rich tapestry of amateur radio. Clarity of thought, extensive experience and an uncanny ability to disseminate that information is the reason you have become an institution (unlike me who needs to be in one).
Thank you for the great tip on shortening a wire antenna without cutting it. I know that many times I've been in a position where once it's cut it's cut. But I got a question for you that I can't seem to find an answer for elsewhere. I have 10 acres and I would like to put telephone poles in around the perimeter of my shack or property if you will and run random wire from pole to pole until it finally comes back to the shack. How do I terminate it and is there a specific length I should work on? Working on 75 meters we had a gentleman that would check in from Scotland almost every night which was rare because although we could hear people on the East Coast and we knew they could hear us they never joined our QSO's. Where in California and there was a echo link station in Erie Pennsylvania with a tunable receiver that we would often use for a signal report. We have a contest between us to see who had the best signal into Pennsylvania. With all drop down to a hundred Watts and see you could be heard the best. Myself in another ham were often the winners. He was a fine operator. I haven't heard him in a while because I've been off the air for medical reasons. But he said his trick was he ran wire and then ran wire and then ran wire. Completely a random length wire antenna. He had a lot of acreage as well. I'd appreciate it if you would address a long wire random length antenna in one of your upcoming videos. I have a SteppIR that's great for 40 meters to 6m but the only option on 80m is almost a half wave dipole on top of the SteppIR. No, I want better. Ideally I'd like something that works on 160 as well. Don't get me wrong because I love the SteppIR! I have one of the original 3 element with the 40 meter option and the additional 6m element. I get such good reports with it I see no reason to upgrade to one of the newer antennas that they have. If it ain't broke don't fix it. My favorite band is 40 meters and it's basically a dipole there. Upgrading to one of the newer antennas would cost me several thousand dollars to get one S unit. I can do an inverted V for 80 off of the tower but like I said I'd like to do 160 as well. Your advice would be most welcome.
Great info, Dave! I have a nice manufactured 10 meter dipole that I want to use on 6 meters. Didn't want to chop it to shorten it, so this is good to know. 73!
Watching it again, made me wonder, when measuring length of wire, from where do you measure? From the end cut, even though wrapped around insulator? From the point the “insulator looped wire” is soldered to a single wire? In other words ... What actual portion of the wire is transmitting, that defines “length”? Would have been great addition to video if while in hand Dave spoke to which portion of the wire he was showing actually counts as “length”. Someone commented that the loop around the insulator isn’t counted in the length (not transmitting)? True?
Everything in the wire is part of your antenna: The loop end, the soldered part, and yes, even the wrapped into itself portion.Wether it transmits or not, it is not that simple. Normally the portion wrapped back becomes part electrically of the outgoing signal but it depends on the wire size and separation of the wrapping and insulation. The important thing is the modification of the wire and if it functions better for you, not the actual length. If after doing the modification you want to measure what length it actually is, most people dont count the loop end.
@@zrdcorp I hope you can reply to this, in perhaps building on Tom W5VLT's question: am I to understand that if I started with a 160m dipole and adjusted it Dave's way - to say become, in length, a 20m dipole, that the 'extra wire' I now have would 'not' effect the 20m? (I'm having a difficult time rationalizing this to myself and need some guidance/clarification - I'm just starting out, no call sign yet, thanks!)
Bryan Zayas ... not understanding, if the RF wavelength doesn’t change by doing as Dave’s video demonstrates, by say folding back 5” of wire from a 20m length of antenna, what’s the point of folding back 5” ? And further based on what you’re saying, if an antenna’s wire is 20m in length exactly (the target length for 20m RF), you’re saying the actual cut length should be 20m even if wrapped around an insulator and back around itself, soldered, so that the actual run width of the antenna is now less than 20m, that the antenna system will function as a whole 20m because it includes the wrap around and twisted soldered portion of the full original 20m cut length?
@@johnstephens6854 You are exaggerating. To go form 160 meters to 20 meters you know you will have a lot of extra wire.... So it does not make any sense not to cut. The technique he shows is for adjustments, not to change from a band to another 8 times smaller....but you know this already.... But to answer your question the extra wire wrapped back onto itself becomes part of the outgoing wire...unless you are doing the 160 to 20 meters, then it becomes something nobody does ... ;-)
@@tomw5vlt119 Nope. Did not say any of that. I am just saying all the wire radiates, but the last part folded or wrapped unto itself is coupled with the wire it is wrapped unto. So it radiates the same signal. So even if the wire is not cut, it radiates as if it was shorter. Unless you make a huge ball of wire or leave a lot of hanging wires, then the thing may act as a capacitance hat which also adds an electrical length to the antenna.
Nice video Dave. Perhaps a video on why does this make the antenna resonate better when you are still using the same amount of wire? For example the super antenna has coils of wire wrapped around a non conductive core to make an overall physically shorter antenna although the same amount of wire is used. How is that different?
That wrapping creates inductance, which loads the antenna somewhat. TO add loading, the manufacturer will add loops of wire much closer together, which creates a lot more inductance than winding with the loops further apart.
Yes, another great idea, to be able to make adjustments when the wire's been soldered on the end(s); however, if one doesn't wanna use solder at the ends (& if ur using bare wire), when calculating actual antenna length, just allow for (add) some extra wire on each end (6" or whatever); then, after looping around (or thru) the end insulator, just wrap that extra wire tightly near the end insulator, then more loosely as u move away from the end(s) & towards the center. I have wire antennas that've been up for years that aren't soldered at the ends but wrapped--still easy to adjust if ever needed. 73 de WA4ELW
If you were to do this on a 10-80 end fed half wave like Mfj sells would it affect all the bands the antenna can receive equally? My end fed wire has much better swr on 3.815 than on 3.963 where I want my swr to be lower. So am I right in thinking that the swr on the rest of the bands this antenna receives will be better on the upper portion of each band the same ad it would on 80?
Whats the length of your actual wire. Mine is 84 with 4 counterpoises of 10 to 30 feet and tunes better on 3.95 tha 3.6 I was thinking of adding a 1/4 wave counterpoise measured for 3.5 ti aee if it helps the tuning at 3.5
Does the bending damage the wire, especially multistrand wire? I suspect the width at a small length doesn't affect the bandwidth, but what would a ball or sphere do?
Dave I enjoy your videos and have a question about portable antennas, I am interested in raising an antenna with a weather balloon and have started building a spool deploy and retrieval system. I’m sure I am not the only one to think of this, do you have any suggestions for this type of deployment?
David, I'm new to radio. I'm installing a GRMS radio as my base station. I want to install an antenna on my home. I'm looking for reviews of either Dr. Ed Fong's antennas or the Hustler G6-450-3. Do you have any thoughts on either radio antenna for the 462 Mhz bands?
Great way to shorten the antenna without cutting the wire, especially cutting it too short. Then you have to add wire which can be done strongly using a scissors knot, but a PITA.
Dave, that’s great for bare wire because electrically it is shortened but what about sheathed cable? with sheathed cable, isn’t it still the same length electrically?
By sheathed I think you mean insulated. The same technique works on insulated wire. Remember, RF works differently from the usual rules for circuits at DC voltages.
Great piece of information here, didn't think of doing it this way. Dave, will this work with insulated wire as well or it needs to be electrically bonded?
It is not dead. If is insulated it is just coupled to the wire it is wrapped to and takes that signal. If it is not insulted it is just electrically connected.
@ 0:26 - 0:30 you've obviously never tried to solder copper to aluminum LOL! just kidding... there are many reasons NOT to join the two. thanks for your videos!!!
David, you are the Mr. Rodgers of Amateur Radio! Your grounded, soft-spoken ham radio episodes are very comforting during this COVID-19 crisis. I"ve subscribed and have been watching your videos for weeks, but wanted you to know how much you are appreciated. Keep up the great work! Thanks 73s Greg, KJ6ER
Thanks for this tip, Dave! I used this method on an MJF-17754 Dipole I recently purchased from DXEngineering. Also, I watched your video, "The MFJ-17754 40/20 Trapped Dipole (#265)", which I'm glad I did because I didn't realize it was shipped with excess wire on both ends. I'm new to HF, but I do have a mobile 2M unit in my Jeep & an HT. I got my Tech two years ago, but decide to jump into the HF area with a Yaesu FT-450D. Due to my HOA, I'm installing my dipole in the attic area. I have a 2-story home, facing south, so I have adequate space in the attic. I'm watching a lot of your videos to educate myself on everything Ham Radio!
I am humbled Dave. Love learning from you. Been a ham since 1986.. but learning more very day.
I wish I had seen this a year ago when I had to cut off the end of a ZS6BKW because it was finished with a heavy duty ferrule permanently crimped on. I couldn't cut through the ferrule to undo it so I had to cut the looped end and insulator off from the antenna. Like your store bought antennas, mine was too long and it resonated below all ham bands. All together I cut off 6 inches, and folded back six more inches after replacing the insulator, making it over a foot shorter at each end to resonate close to the middle of the bands. In all fairness It's not at least 40' in the air as recommended, but rather 27', naturally making it perform as though it's too long. This is a really good antenna trimming tip. Thanks Dave.
Tnx Dave. I needed a simple way to this when I take my antenna down. I have just been rollin’ with 2.5 SWR for now.
You're looking healthier and more rested every day. Whatever you're doing, keep it up!
Very cool. Well demonstrated. Try describe that in text only - would take a page and I'd still be clueless. Thank you!
I think I finally understand antenna length measurement.
Love these short-form videos. 73s de NK3PS
Thanks for answering my question. On my insulated end fed half wave I will just neatly tape the wire back on itself.
With electrical tape?
@@denelson83 It is what I used. Some 3M stuff I had.
Good method, never thought of doing that way myself. Thank you.
I never thought of that!
That’s pretty next level genius idea.
Thanks for that.
Great video! The sound and lighting is perfict. Your inforrmation is always quite usefull. 73-KD9HWH
This is exactly the sort of detail that most skip over. An integral part of the electronics and engineering which form part of the rich tapestry of amateur radio. Clarity of thought, extensive experience and an uncanny ability to disseminate that information is the reason you have become an institution (unlike me who needs to be in one).
Thank you for the great tip on shortening a wire antenna without cutting it. I know that many times I've been in a position where once it's cut it's cut.
But I got a question for you that I can't seem to find an answer for elsewhere. I have 10 acres and I would like to put telephone poles in around the perimeter of my shack or property if you will and run random wire from pole to pole until it finally comes back to the shack. How do I terminate it and is there a specific length I should work on?
Working on 75 meters we had a gentleman that would check in from Scotland almost every night which was rare because although we could hear people on the East Coast and we knew they could hear us they never joined our QSO's. Where in California and there was a echo link station in Erie Pennsylvania with a tunable receiver that we would often use for a signal report. We have a contest between us to see who had the best signal into Pennsylvania. With all drop down to a hundred Watts and see you could be heard the best. Myself in another ham were often the winners.
He was a fine operator. I haven't heard him in a while because I've been off the air for medical reasons. But he said his trick was he ran wire and then ran wire and then ran wire. Completely a random length wire antenna. He had a lot of acreage as well.
I'd appreciate it if you would address a long wire random length antenna in one of your upcoming videos. I have a SteppIR that's great for 40 meters to 6m but the only option on 80m is almost a half wave dipole on top of the SteppIR. No, I want better. Ideally I'd like something that works on 160 as well. Don't get me wrong because I love the SteppIR! I have one of the original 3 element with the 40 meter option and the additional 6m element. I get such good reports with it I see no reason to upgrade to one of the newer antennas that they have. If it ain't broke don't fix it. My favorite band is 40 meters and it's basically a dipole there. Upgrading to one of the newer antennas would cost me several thousand dollars to get one S unit. I can do an inverted V for 80 off of the tower but like I said I'd like to do 160 as well.
Your advice would be most welcome.
Good idea. New folks need practical ideas like this. Thanks!
Nice. This is what I have done over the years. I am glad you did not complicated nautical knots. I can't do any of them. Peace and Happiness
Great info, Dave! I have a nice manufactured 10 meter dipole that I want to use on 6 meters. Didn't want to chop it to shorten it, so this is good to know. 73!
Watching it again, made me wonder, when measuring length of wire, from where do you measure? From the end cut, even though wrapped around insulator? From the point the “insulator looped wire” is soldered to a single wire? In other words ... What actual portion of the wire is transmitting, that defines “length”?
Would have been great addition to video if while in hand Dave spoke to which portion of the wire he was showing actually counts as “length”. Someone commented that the loop around the insulator isn’t counted in the length (not transmitting)? True?
Everything in the wire is part of your antenna: The loop end, the soldered part, and yes, even the wrapped into itself portion.Wether it transmits or not, it is not that simple. Normally the portion wrapped back becomes part electrically of the outgoing signal but it depends on the wire size and separation of the wrapping and insulation.
The important thing is the modification of the wire and if it functions better for you, not the actual length.
If after doing the modification you want to measure what length it actually is, most people dont count the loop end.
@@zrdcorp I hope you can reply to this, in perhaps building on Tom W5VLT's question: am I to understand that if I started with a 160m dipole and adjusted it Dave's way - to say become, in length, a 20m dipole, that the 'extra wire' I now have would 'not' effect the 20m? (I'm having a difficult time rationalizing this to myself and need some guidance/clarification - I'm just starting out, no call sign yet, thanks!)
Bryan Zayas ... not understanding, if the RF wavelength doesn’t change by doing as Dave’s video demonstrates, by say folding back 5” of wire from a 20m length of antenna, what’s the point of folding back 5” ?
And further based on what you’re saying, if an antenna’s wire is 20m in length exactly (the target length for 20m RF), you’re saying the actual cut length should be 20m even if wrapped around an insulator and back around itself, soldered, so that the actual run width of the antenna is now less than 20m, that the antenna system will function as a whole 20m because it includes the wrap around and twisted soldered portion of the full original 20m cut length?
@@johnstephens6854 You are exaggerating. To go form 160 meters to 20 meters you know you will have a lot of extra wire.... So it does not make any sense not to cut. The technique he shows is for adjustments, not to change from a band to another 8 times smaller....but you know this already....
But to answer your question the extra wire wrapped back onto itself becomes part of the outgoing wire...unless you are doing the 160 to 20 meters, then it becomes something nobody does ... ;-)
@@tomw5vlt119 Nope. Did not say any of that. I am just saying all the wire radiates, but the last part folded or wrapped unto itself is coupled with the wire it is wrapped unto. So it radiates the same signal. So even if the wire is not cut, it radiates as if it was shorter. Unless you make a huge ball of wire or leave a lot of hanging wires, then the thing may act as a capacitance hat which also adds an electrical length to the antenna.
Neat technique!! Thanks Sir! (Hints and kinks picked up over your many years!!) Super solution, Mr Casler! God Bless!!..73's, K6PAM
Nice tip. Thanks for your work. Keep breathin'.
Amazingly simple and quite effective!! Thanks David!!
You're keeping us all busy, thank you....fyi just purchased AnyTone AT-D878UV PLUS...thanks in part to your and others' videos! 73 K4QJS hoop
I think you'll really enjoy that radio.
Easy solution that is reversible. Thanks Dave, KQ7R
Nice video Dave. Perhaps a video on why does this make the antenna resonate better when you are still using the same amount of wire? For example the super antenna has coils of wire wrapped around a non conductive core to make an overall physically shorter antenna although the same amount of wire is used. How is that different?
That wrapping creates inductance, which loads the antenna somewhat. TO add loading, the manufacturer will add loops of wire much closer together, which creates a lot more inductance than winding with the loops further apart.
Yes, another great idea, to be able to make adjustments when the wire's been soldered on the end(s); however, if one doesn't wanna use solder at the ends (& if ur using bare wire), when calculating actual antenna length, just allow for (add) some extra wire on each end (6" or whatever); then, after looping around (or thru) the end insulator, just wrap that extra wire tightly near the end insulator, then more loosely as u move away from the end(s) & towards the center. I have wire antennas that've been up for years that aren't soldered at the ends but wrapped--still easy to adjust if ever needed. 73 de WA4ELW
If you were to do this on a 10-80 end fed half wave like Mfj sells would it affect all the bands the antenna can receive equally? My end fed wire has much better swr on 3.815 than on 3.963 where I want my swr to be lower. So am I right in thinking that the swr on the rest of the bands this antenna receives will be better on the upper portion of each band the same ad it would on 80?
Whats the length of your actual wire. Mine is 84 with 4 counterpoises of 10 to 30 feet and tunes better on 3.95 tha 3.6
I was thinking of adding a 1/4 wave counterpoise measured for 3.5 ti aee if it helps the tuning at 3.5
David Casler - just found this, my EFHW is about 6 feet too long, how would i shorten that w/o cutting/ same as above?
Could you show this method using insulated wire and shortening 2 foot, thank you
Does the bending damage the wire, especially multistrand wire?
I suspect the width at a small length doesn't affect the bandwidth, but what would a ball or sphere do?
AG7MW
A little extra width at the end won't affect the antenna.
Dave I enjoy your videos and have a question about portable antennas, I am interested in raising an antenna with a weather balloon and have started building a spool deploy and retrieval system. I’m sure I am not the only one to think of this, do you have any suggestions for this type of deployment?
David, I'm new to radio. I'm installing a GRMS radio as my base station. I want to install an antenna on my home. I'm looking for reviews of either Dr. Ed Fong's antennas or the Hustler G6-450-3. Do you have any thoughts on either radio antenna for the 462 Mhz bands?
I simply make a loop and feed the bend through a short length of silicone wire insulation: instant sliding adjustment and no kinks!
Can you show us how that's done?
Great way to shorten the antenna without cutting the wire, especially cutting it too short. Then you have to add wire which can be done strongly using a scissors knot, but a PITA.
would it be possible to review the bushcraft MA5B or MA6B ? Its a small Yagi that would fit well at my place... thanks and 73 !
Dave, that’s great for bare wire because electrically it is shortened but what about sheathed cable? with sheathed cable, isn’t it still the same length electrically?
By sheathed I think you mean insulated. The same technique works on insulated wire. Remember, RF works differently from the usual rules for circuits at DC voltages.
Loved the Pi reference! Lol
I wish I had gotten into amateur radio before the pandemic. It would have made the days more interesting.
Hey David. Thank you. Can be done with pvc insulated wire? Wraped with cable ties maybe?
Insulated wire works fine for wire antenna, though you may find that it will affect the dimensions a bit, making them a little shorter.
Does the insulation affect the electrical length? Aka does it need to be shorted back to itself to prevent creating some weird coil induction?
Thanks for this good antenna tip. 73 from Germany de Michael, DL2YMR
Great idea Dave
Good Stuff Dave.
No wonder the MFJ adjustment formulae didn't work for you. The extra twisted up wire, particularly for insulated wire, still affects tuning.
That is very slick!
great show
Great piece of information here, didn't think of doing it this way. Dave, will this work with insulated wire as well or it needs to be electrically bonded?
GOOD TIP
That's clever! Thank you!
Thank you
Thank you for the reminder. N0QFT
Thanks
hi, what if the wire is insulated and you need to shorten it
BILL MILLAR works the same with insulated
When wire is folded back on itself what makes it electrically dead so it doesn’t radiate?? Always wondered that.....
It is not dead. If is insulated it is just coupled to the wire it is wrapped to and takes that signal. If it is not insulted it is just electrically connected.
Thank you. Have a great week. N0QFT
@ 0:26 - 0:30 you've obviously never tried to solder copper to aluminum LOL!
just kidding... there are many reasons NOT to join the two.
thanks for your videos!!!
Thinks
Roll a joint antenna 📶 systems dont be frugie 100000000feet 😅dump the mfj jr go whooping 😮
Hilarious 🤪
Hope y'all realize now that you stayed home for no tangible reason.
Rubbish - Now try it with insulated antenna wire.
Hi Guys how do your shorten the centre section of a trap dipole without disconnecting the ends, fold it in the middle somehow......g4vvq.