Am getting back into QRP after a 40 year hiatus. Back then sunspot #'s were higher hi hi. Right now the antenna at the shack is a 31' vertical, ground mounted, 50 buried radials, about 280' ASL. Going to see how that works but was wondering what antennas others use for QRP operation. Yes I know digital modes might be better but am interested in CW only, maybe a little SSB if band is in good condx. Tnx and 73's.
Antennas for QRP Operation
- Thread starter spongella
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prcguy
Member
I've been doing a lot of QRP SSB over the last 20yrs and your antenna is key to making good contacts with the lousy band conditions we have right now. When the Yaesu FT-817 came out around 2004 band conditions were great and you could talk all over the place with a Buddistick or small low performing antenna. Not now, your antenna needs to make up for the low power and band conditions.
So far the best all around antenna I've found for performance and portability is a resonant end fed half wave using a 49:1 or 64:1 transformer with the radiating wire and guy string wound up in a plastic chalk line reel. This is a very small antenna for carrying around and it goes up in about a minute and take down is even faster. The performance is about the same as a full size 1/2 wave dipole at the same height.
The basic version I use covers 40, 20, 15 and 10m with no tuner and the transformer will work with any 1/2 wavelength of wire and also works on odd and even harmonics of its design freq. It has about 64ft of 22ga Teflon wire with about 40ft of miniature parachute cord attached. You unspool all the wire and cord, then the empty chalk line reel is your throw weight to get the far end over a tree, etc. The transformer is about the size of a Zippo lighter and handles up to about 100w.
I usually carry another chalk line reel with about 80ft of mini parachute cord to use as a guy string on the transformer side of the antenna. That gives you enough wire and string to span up to about 180ft between trees or whatever you can find to hang the antenna on. Here is a picture of one with some tiny feedline and common mode choke built into the coax.
So far the best all around antenna I've found for performance and portability is a resonant end fed half wave using a 49:1 or 64:1 transformer with the radiating wire and guy string wound up in a plastic chalk line reel. This is a very small antenna for carrying around and it goes up in about a minute and take down is even faster. The performance is about the same as a full size 1/2 wave dipole at the same height.
The basic version I use covers 40, 20, 15 and 10m with no tuner and the transformer will work with any 1/2 wavelength of wire and also works on odd and even harmonics of its design freq. It has about 64ft of 22ga Teflon wire with about 40ft of miniature parachute cord attached. You unspool all the wire and cord, then the empty chalk line reel is your throw weight to get the far end over a tree, etc. The transformer is about the size of a Zippo lighter and handles up to about 100w.
I usually carry another chalk line reel with about 80ft of mini parachute cord to use as a guy string on the transformer side of the antenna. That gives you enough wire and string to span up to about 180ft between trees or whatever you can find to hang the antenna on. Here is a picture of one with some tiny feedline and common mode choke built into the coax.
While I continue to use various quick deploy antennas, the current favorite is the Chameleon Loop. I'm not working DX mind you, but Hawaii and the U.S. are okay, Canada and Mexico too. This has all been via SSB. I am still looking for the three piece "high efficiency loop" they previously made and give it a whirl. They sell the two piece, but the three will break down better for my use.
Thinking about it further...I should setup a vertical solution as well next time. Float an elevated counterpoise rolled out for the band and see what I can catch as well as compare the two.
I quite like QRP as it requires critical thinking and testing the antenna half of the system. Still, I am eager to use some brute force of power here in the near future. The upcoming Icom 705 will allow me to punch 10 watts and really crunch the bands!
Thinking about it further...I should setup a vertical solution as well next time. Float an elevated counterpoise rolled out for the band and see what I can catch as well as compare the two.
I quite like QRP as it requires critical thinking and testing the antenna half of the system. Still, I am eager to use some brute force of power here in the near future. The upcoming Icom 705 will allow me to punch 10 watts and really crunch the bands!
prcguy
Member
I've tried a number of portable verticals over the years and they all have been a disappointment. Many years ago before I discovered the EFHW my main portable antenna was a G5RV made with lightweight TV twinlead and the same chalk line idea for the elements. I used it with a 33ft telescoping fiberglass mast as an inverted V and it worked 80 through 10m quite well.
I wanted better performance on 40m DX so I made a full size 32ft vertical with a wire up the fiberglass mast and worked it against four 20ft long radials. I was sure this full size 1/4 wave vertical would outperform a G5RV with its apex at 30ft and the ends only 6ft off the ground. After checking into my usual evening net running a military manpack I swapped between the vertical and the G5RV many times while stations from coast to coast reported the results. The low G5RV was much better.
I've had similar results with most verticals except for my 43ft DX engineering vertical with auto tuner at the base and 30 something radials about 30ft long each over a wet marsh. That slightly outperforms a ZS6BKW on 40 and 20m on DX, but the ZS6BKW is much more useful working both low angle DX and NVIS mode that the vertical does not get. If my portable 40m 1/4 wave vertical had a lot more radials and they were elevated it probably would have outdone the G5RV but with a lot more parts and hassle.
I wanted better performance on 40m DX so I made a full size 32ft vertical with a wire up the fiberglass mast and worked it against four 20ft long radials. I was sure this full size 1/4 wave vertical would outperform a G5RV with its apex at 30ft and the ends only 6ft off the ground. After checking into my usual evening net running a military manpack I swapped between the vertical and the G5RV many times while stations from coast to coast reported the results. The low G5RV was much better.
I've had similar results with most verticals except for my 43ft DX engineering vertical with auto tuner at the base and 30 something radials about 30ft long each over a wet marsh. That slightly outperforms a ZS6BKW on 40 and 20m on DX, but the ZS6BKW is much more useful working both low angle DX and NVIS mode that the vertical does not get. If my portable 40m 1/4 wave vertical had a lot more radials and they were elevated it probably would have outdone the G5RV but with a lot more parts and hassle.
Damn, I too am sure the vertical you described would have outperformed the G5RV with at least two 20' radials, let alone four. That's weird. Stupid testing giving us facts versus theory.
If I am going to be at a spot for more than a day, I typically hoist up a 6-40m inverted V OCF. I enjoy having the spread of multiple bands and often I dial around listening to other non-amateur stuff. I choke it at the feedpoint and again at the radio to keep things friendly on TX. I rigged a way for one person to deploy it using a mast and without requiring guy lines. I should take a pictures next time. It is secured at the base with either a tilt / anchoring thing I made, or in a hitch flag pole holder on the vehicle. Due to the weight of the balun, choke, and coax I use six of the military aluminum masts for most of it, with three fiberglass one's near the apex. It's still relatively quick to deploy and breakdown. The nine mast pieces take up space though. ( I should note I sometimes use 20w with an 897D with the OCF like that. )
I've watched a friend use his Codan manpack with the supplied vertical antenna right on the radio. He throws a short bit of ground wire with a clamp on the ground, or clips it to something if available. He's pushing 20 watts and gets results. Better than I did using 5W and a Buddipole in an L configuration. Of course that 20 watts brings the extra dB.
If I am going to be at a spot for more than a day, I typically hoist up a 6-40m inverted V OCF. I enjoy having the spread of multiple bands and often I dial around listening to other non-amateur stuff. I choke it at the feedpoint and again at the radio to keep things friendly on TX. I rigged a way for one person to deploy it using a mast and without requiring guy lines. I should take a pictures next time. It is secured at the base with either a tilt / anchoring thing I made, or in a hitch flag pole holder on the vehicle. Due to the weight of the balun, choke, and coax I use six of the military aluminum masts for most of it, with three fiberglass one's near the apex. It's still relatively quick to deploy and breakdown. The nine mast pieces take up space though. ( I should note I sometimes use 20w with an 897D with the OCF like that. )
I've watched a friend use his Codan manpack with the supplied vertical antenna right on the radio. He throws a short bit of ground wire with a clamp on the ground, or clips it to something if available. He's pushing 20 watts and gets results. Better than I did using 5W and a Buddipole in an L configuration. Of course that 20 watts brings the extra dB.
prcguy
Member
In the late 90s I used to check into my coast to coast evening 40m net with a PRC-70 manpack on the lawn at work with its attached 9ft whip and I used four radials about 10ft long each. I was heard from CA to NM, CO, some midwestern states, NY and Fl no problem. I also remember tossing about 25ft of wire onto the lawn with no counterpoise with my manpack radio and having a mid day chat on 40m to a bunch of people including Art Bell W6OBB in Nevada. Can't do that today with the crappy propagation. Not to mention Art is a SK.
When the Elecraft KX3 was first released I got a fairly early one and traveled all over the US with the radio at 5 or 10w and the chalk line 40-10m EFHW. It never failed to contact anyone I could hear even if they were running legal limit and it all packed into a tiny Maxpedition shoulder bag like this: Remora Gearslinger (BFCM Sale. Buy-1-Get-1-Free. Add multiples of 2 to qualify. Final Sale.)
The chalk line reel EFHW will pack into just about anything and put out a big signal.
When the Elecraft KX3 was first released I got a fairly early one and traveled all over the US with the radio at 5 or 10w and the chalk line 40-10m EFHW. It never failed to contact anyone I could hear even if they were running legal limit and it all packed into a tiny Maxpedition shoulder bag like this: Remora Gearslinger (BFCM Sale. Buy-1-Get-1-Free. Add multiples of 2 to qualify. Final Sale.)
The chalk line reel EFHW will pack into just about anything and put out a big signal.
I like that the chalk wheel is the weight and it is all quite tidy. I will more than likely emulate your kit and give it a whirl. It's just too compact not to try, plus another with the paracord as you noted.
I forgot to add that it seemed odd to me my buddy's Codan setup did not include a counterpoise, especially due to the cost. I probably rattled off something about counterpoise during our field work fun. He later opened a pocket on his pack and pulled out a four wire counterpoise with some adapter and asked if this would help. My eyes almost rolled out of their sockets. I advised him to use that every time and why. Good times.
I forgot to add that it seemed odd to me my buddy's Codan setup did not include a counterpoise, especially due to the cost. I probably rattled off something about counterpoise during our field work fun. He later opened a pocket on his pack and pulled out a four wire counterpoise with some adapter and asked if this would help. My eyes almost rolled out of their sockets. I advised him to use that every time and why. Good times.
prcguy
Member
I've probably got 10,000+ft of the miniature paracord in several colors, let me know if you need some. Its about the same size as 22ga Teflon wire and it holds up to 200lbs ok. The blue Irwin chalk line reel holds more than the yellow ones.
prcguy
Member
For vagrant, about 150ft of mini para cord, 65ft of 22ga silver plated Teflon wire, an FT-140-43 ferrite core for the transformer, a #31 mix large bead for a feedline choke, a 120pf 1kV cap, a box, BNC connector and stainless eye bolt are on the way to you.
For anyone else, here are plans to make a 49:1 or 64:1 transformer for a resonant EFHW at the bottom of this post. I believe the large #31 ferrite bead I sent vagrant is an FB-31-1020 and you wrap 6 or eight turns of minature coax through the bead about 2ft from the radio end to make a common mode choke. For this particular 100w portable end fed shown in post #2 above, I like to use about 30ft of RG-316 Teflon coax or LMR100 since its tiny and packs light. Several feet will be used up wrapping around the large ferrite bead leaving a good 25ft of coax to feed the antenna for portable field use.
If you have a dual port antenna antenna analyzer or scaler/vector network analyzer you can set up a pair of coax to binding post adapters, short the grounds together and put some test windings around the common mode choke ferrite bead and attach between the hot posts of the coax to binding post adapters. You can then tune the number of turns around the ferrite bead to target your main frequency range for the most isolation on the analyzer. If you operate more on 40m then more turns will favor the lower freqs. Less turns will favor 20 through 10m. You can then cover the core and windings with some electrical tape to keep things from unwinding or use some large heat shrink as in the picture in post #2.
For the overall end fed antenna project you first wind the 64:1 transformer then set it in the tiny box to then locate the holes for the connector (BNC in this case) and a screw that will be the connection for the wire element. You also need to install a very small eye bolt to attach a guy string.
If the box is sitting in front of you the transformer goes roughly in the middle, the output screw would go in the upper right, the coax connector in the lower left and the eye bolt in the upper left opposite the wire attachment. The hole for the eye bolt will drill in the edge of the box but the wire connection screw will be in the face of the box perpendicular to the eyebolt because you want the pulling force on a wire lug to be straight in line with the wire and if you put the wire attachment screw on the edge of the box the wire lug will be bent in half weakening it. The coax connector goes low on the box so the attached coax naturally hangs downward.
Never mind that the box in post 2 shows the wire attaching screw and the BNC connector are more in the middle of the box, try to keep the wire attachment screw in the far upper corner, which would be more to the left in the picture and put the coax connector more to the right in the picture. Otherwise when you put up your antenna, children will look up and point, knowing this is your first end fed project.
For tuning first use a resistor from the output to ground as mentioned in the link below to make sure the transformer matches around 3,200 ohms to 50 ohms well, then attach about 64ft of wire and trim for the best compromise between 40 and 20m. this is usually around 7.125Mhz on 40 which should match best around 14.250 on 20m. The antenna should then cover the entire bands without needing a tuner.
All of this info will help make what I think is the best all around 40-10m portable antenna for QRP work, its very efficient, lightweight and easy to put up and take down. Here are some plans for winding the transformer but they are using a much larger ferrite core and installing a loading coil for 80m. The FT-140-43 core I'm recommending for a tiny 100w portable version will probably not go down to 80m very well, and if it did you would use about 133ft of wire and add a capacitor around 150pf in the middle of the antenna to bring the resonant point up to about 3.9MHz instead of the natural resonance around 3.55MHz, which is not that useful. There is more to this if someone wants to make an 80-10m version, just ask.
buildthings.wordpress.com
For anyone else, here are plans to make a 49:1 or 64:1 transformer for a resonant EFHW at the bottom of this post. I believe the large #31 ferrite bead I sent vagrant is an FB-31-1020 and you wrap 6 or eight turns of minature coax through the bead about 2ft from the radio end to make a common mode choke. For this particular 100w portable end fed shown in post #2 above, I like to use about 30ft of RG-316 Teflon coax or LMR100 since its tiny and packs light. Several feet will be used up wrapping around the large ferrite bead leaving a good 25ft of coax to feed the antenna for portable field use.
If you have a dual port antenna antenna analyzer or scaler/vector network analyzer you can set up a pair of coax to binding post adapters, short the grounds together and put some test windings around the common mode choke ferrite bead and attach between the hot posts of the coax to binding post adapters. You can then tune the number of turns around the ferrite bead to target your main frequency range for the most isolation on the analyzer. If you operate more on 40m then more turns will favor the lower freqs. Less turns will favor 20 through 10m. You can then cover the core and windings with some electrical tape to keep things from unwinding or use some large heat shrink as in the picture in post #2.
For the overall end fed antenna project you first wind the 64:1 transformer then set it in the tiny box to then locate the holes for the connector (BNC in this case) and a screw that will be the connection for the wire element. You also need to install a very small eye bolt to attach a guy string.
If the box is sitting in front of you the transformer goes roughly in the middle, the output screw would go in the upper right, the coax connector in the lower left and the eye bolt in the upper left opposite the wire attachment. The hole for the eye bolt will drill in the edge of the box but the wire connection screw will be in the face of the box perpendicular to the eyebolt because you want the pulling force on a wire lug to be straight in line with the wire and if you put the wire attachment screw on the edge of the box the wire lug will be bent in half weakening it. The coax connector goes low on the box so the attached coax naturally hangs downward.
Never mind that the box in post 2 shows the wire attaching screw and the BNC connector are more in the middle of the box, try to keep the wire attachment screw in the far upper corner, which would be more to the left in the picture and put the coax connector more to the right in the picture. Otherwise when you put up your antenna, children will look up and point, knowing this is your first end fed project.
For tuning first use a resistor from the output to ground as mentioned in the link below to make sure the transformer matches around 3,200 ohms to 50 ohms well, then attach about 64ft of wire and trim for the best compromise between 40 and 20m. this is usually around 7.125Mhz on 40 which should match best around 14.250 on 20m. The antenna should then cover the entire bands without needing a tuner.
All of this info will help make what I think is the best all around 40-10m portable antenna for QRP work, its very efficient, lightweight and easy to put up and take down. Here are some plans for winding the transformer but they are using a much larger ferrite core and installing a loading coil for 80m. The FT-140-43 core I'm recommending for a tiny 100w portable version will probably not go down to 80m very well, and if it did you would use about 133ft of wire and add a capacitor around 150pf in the middle of the antenna to bring the resonant point up to about 3.9MHz instead of the natural resonance around 3.55MHz, which is not that useful. There is more to this if someone wants to make an 80-10m version, just ask.
Ham Radio End Fed Antenna with a 1:64 Matching Network
The Experiment: In this experiment were going to explore the use of a 1:64 Matching Auto Transformer on the End Fed Long Wire Antenna. I have read a lot of post on the internet regarding the great …
buildthings.wordpress.com
What?! I have to put it together as well?! hahaha 
I picked up two chalk wheels yesterday. I also found my Kester "44" roll of solder I misplaced. I am eager to build and test it as I have a few three day weekends coming up. 10-40 is just what I'm looking for. Thanks again.
I picked up two chalk wheels yesterday. I also found my Kester "44" roll of solder I misplaced. I am eager to build and test it as I have a few three day weekends coming up. 10-40 is just what I'm looking for. Thanks again.
Well this is timely to the thread. I just spotted a for sale post on QRZ of some very small transformers. 80-10 meters and 100W. While small, one wonders about durability and what's going on under the coating. Still, pretty cool for keeping it small and handling 100 watts.
prcguy
Member
Interesting but how would you attach a guy string going opposite the wire to hold everything high in the air? $40 for these is probably not bad but the ferrite core is under $3, the connector is about $2.50 and you can wind the transformer in about 10min. I like my small box version better.
Well this is timely to the thread. I just spotted a for sale post on QRZ of some very small transformers. 80-10 meters and 100W. While small, one wonders about durability and what's going on under the coating. Still, pretty cool for keeping it small and handling 100 watts.
Come on man. You're supposed to let the thread watchers compare the two and figure out the better solution. Critical thinking is a skill that needs to be developed. That's why I only hinted about the durability.
- $10 worth of parts, some time and sense of accomplishment is better than $40
- On that version one would pull the coaxial cable as the guy line...yeah risky. (see that link and the other photo they posted)
- Also on that link is some kind of sweep where they felt the need to show up to 25 VSWR, instead of adjusting for just 1 - 5. They then drew in 1.5 and 2.0 SWR lines across the graph.
Anyways, I've got some 20 ga enameled wire rolling in tomorrow and prepped the Irwin chalk boxes today. I need to find my glue gun.
- $10 worth of parts, some time and sense of accomplishment is better than $40
- On that version one would pull the coaxial cable as the guy line...yeah risky. (see that link and the other photo they posted)
- Also on that link is some kind of sweep where they felt the need to show up to 25 VSWR, instead of adjusting for just 1 - 5. They then drew in 1.5 and 2.0 SWR lines across the graph.
Anyways, I've got some 20 ga enameled wire rolling in tomorrow and prepped the Irwin chalk boxes today. I need to find my glue gun.
prcguy
Member
What is the glue gun for? If you use hot glue near the ferrite core and it gets a little warm it will just melt the hot glue. I use clear silicone adhesive to hold the ferrite core in the box and don't ever use black silicone for that, I found it detunes things.
Will do on the clear silicone. I think I used up my last tube of it, or have just a bit left. Truly though, I did not think the core would get hot enough to re-melt a glue stick compound. Now I wonder how hot that core can get with say 5, 50 and 100 watts over time. Sounds like more experimenting fun to come. Anyways, now that I stopped looking for the glue gun I'll probably find it.
prcguy
Member
The FT-140-43 core will do 100w SSB just fine but not AM or FM, maybe 50w or so for that. You can use a much larger FT-240-43 core for up to 400w SSB or stack two FT-240-52 cores for about 800w or three FT-240-52 cores for legal limit. When you stack cores its better to use lower permeability since the inductance doubles when you stack them and the 52 mix seems best for this. I do have an older unit with two stacked FT-240-43 cores that has taken 1,200w without any problems but a long key down with lots of compression or processing would eventually overheat things.
Here is a picture of the insides of a MyAntennas 2kW rated transformer using three FT-240 size cores. I took this transformer out of its original box and put it in the typical boxes I use, which I think are better than what MyAntennas uses.
Here is a picture of the insides of a MyAntennas 2kW rated transformer using three FT-240 size cores. I took this transformer out of its original box and put it in the typical boxes I use, which I think are better than what MyAntennas uses.
Here are antennas I have tried and still use depending on the situation like no trees, or quick setup/takedown. Happy to answer questions if any.
In no particular order:
1. Buddipole - I use this horizontal, vertical, L config or vertical with elevated wire counterpoise length for the band.
2. Opek HVT-400B - This one is used on my vehicle luggage rack with wires connecting the shield to the roof for a ground. Plus some ferrites for a choke. I like it because I can run it vertical or horizontal for NVIS because of the mount, plus band change is easy.
3. Icom AH-703 - An interesting antenna and like prcguy noted, when conditions are good even poor antennas will work. I usually use it for RX as it is quick to get resonant from 40-6 meters and breaks down easily fitting into a PVC tube with caps. This antenna is supplied with a counterpoise of two equal strand lengths of five meters of wire.
4. A handful of various band Hamsticks. Original versions that I have never used, other than the 6m. I need to swap these where I place the Opek and really try them out.
5. Chameleon loop - As previously mentioned
6. OCF - Again as previously mentioned and used in an inverted V config.
* 7. EFHW - The soon to be built end fed
I have two favorite antennas not listed I have used for QRP. These two are not that mobile/portable.
1. Mosley TA-33 Jr. - At 50' AGL, this three element, three band antenna was so much fun to use QRP.
2. K4KIO - I use this Hexagonal beam at home.
Wait, there is a third antenna I have only used once. It was a KT36XA.
I need convey that after using the above "portable" antennas and then using these three, it is like upgrading from a rowboat to a yacht on both TX and RX, especially with the Mosley and M2 KT36XA. The meter swings away allowing those five watts, or whatever eventually hits the antenna, to really exercise their RF legs. Some operators had a difficult time believing that I was only using an 817 with five watts. I advised of the antenna I was using at the time and some accepted it. Still, others were not convinced I was QRP, especially when they were on the backside of the beam.
I'll probably purchase a solid state 500W amplifier one day. Then when they do not believe me at 5W, I may spice things up.
In no particular order:
1. Buddipole - I use this horizontal, vertical, L config or vertical with elevated wire counterpoise length for the band.
2. Opek HVT-400B - This one is used on my vehicle luggage rack with wires connecting the shield to the roof for a ground. Plus some ferrites for a choke. I like it because I can run it vertical or horizontal for NVIS because of the mount, plus band change is easy.
3. Icom AH-703 - An interesting antenna and like prcguy noted, when conditions are good even poor antennas will work. I usually use it for RX as it is quick to get resonant from 40-6 meters and breaks down easily fitting into a PVC tube with caps. This antenna is supplied with a counterpoise of two equal strand lengths of five meters of wire.
4. A handful of various band Hamsticks. Original versions that I have never used, other than the 6m. I need to swap these where I place the Opek and really try them out.
5. Chameleon loop - As previously mentioned
6. OCF - Again as previously mentioned and used in an inverted V config.
* 7. EFHW - The soon to be built end fed
I have two favorite antennas not listed I have used for QRP. These two are not that mobile/portable.
1. Mosley TA-33 Jr. - At 50' AGL, this three element, three band antenna was so much fun to use QRP.
2. K4KIO - I use this Hexagonal beam at home.
Wait, there is a third antenna I have only used once. It was a KT36XA.
I need convey that after using the above "portable" antennas and then using these three, it is like upgrading from a rowboat to a yacht on both TX and RX, especially with the Mosley and M2 KT36XA. The meter swings away allowing those five watts, or whatever eventually hits the antenna, to really exercise their RF legs. Some operators had a difficult time believing that I was only using an 817 with five watts. I advised of the antenna I was using at the time and some accepted it. Still, others were not convinced I was QRP, especially when they were on the backside of the beam.
I'll probably purchase a solid state 500W amplifier one day. Then when they do not believe me at 5W, I may spice things up.
Items arrived today. Thank you.
--- Never mind this below. I just re-read your note above instead of just looking at the image...moving forward. ---
I was thinking about the layout of the transformer you show in the photograph and it seems an alternate layout may be better. See the image I edited below. This alternate layout would provide some space inside, as well as keep the antenna wire and pull/guy line across from each other. By moving the BNC and the antenna to the corners, it would seem to also provide additional strength. Additionally, the eye loop I would put on the same side of the box, which it appears you did, so as not to introduce stresses on both halves. I'm not sure if you sealed that box, or used a small screw or what. I'll initially tape it while testing/sweeping.
Your thoughts?
--- Never mind this below. I just re-read your note above instead of just looking at the image...moving forward. ---
I was thinking about the layout of the transformer you show in the photograph and it seems an alternate layout may be better. See the image I edited below. This alternate layout would provide some space inside, as well as keep the antenna wire and pull/guy line across from each other. By moving the BNC and the antenna to the corners, it would seem to also provide additional strength. Additionally, the eye loop I would put on the same side of the box, which it appears you did, so as not to introduce stresses on both halves. I'm not sure if you sealed that box, or used a small screw or what. I'll initially tape it while testing/sweeping.
Your thoughts?
Last edited:
prcguy
Member
Yes, that is how I build them with the eye bolt and antenna wire connection in line and the coax connector off to one side and the eye bolt and wire screw on the same side (half) of the box for strength. The box has a tiny black screw inside when you first open the package, don't loose the screw. You only need the screw to hold it together and it doesn't need any sealant. A little water inside won't hurt anything and some sun on the black surface will dry it up quick.
Is it built yet? Are we on the air???
Is it built yet? Are we on the air???
I was testing some knots and first tried a fisherman's with the wire and line, but a square knot works better (smaller) than fisherman or bowline. I trimmed the ends and some small shrink tubing keeps it neat. I then used that square knot test piece to slip in/out of the Irwin chalk box and enlarged the hole as needed. I purchased the aluminum Irwin, so I had some sharp edges to remove after drilling. Only a slight weight difference, so the ABS version would be fine too or better. As you noted, that feed line is quite strong. I pulled on the fisherman's knot test piece and the wire gave way before the line.
No screw in that black box. It never rattled like a screw was in there and the package was sealed. Not an issue really, I'll rig something, or just leave the tape on. I just found a proper length screw, nut, washer and wing nut I had on hand, so I should be able to start the build tomorrow and test it out.
No screw in that black box. It never rattled like a screw was in there and the package was sealed. Not an issue really, I'll rig something, or just leave the tape on. I just found a proper length screw, nut, washer and wing nut I had on hand, so I should be able to start the build tomorrow and test it out.
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