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Posted: 3/2/2024 3:00:14 PM EDT
Has anyone used or tried one? I already have a good 9:1 balun and I just ordered a resister. Already have the wire too.
Purpose - I'm mostly toying with this to add 160m and 60m to the shack. Deployment - I plan to install the feed point 10' up the same pole that I have my EFHW-7510 mounted to at 15'. EFHW runs E-W and is connected to my back up radio (TS-590SG). I will connect this to the same radio antenna 2 port and run the wire perpendicular to the EFHW. Resistor I found: https://palomar-engineers.com/tech-support/tech-topics/ferrite-tutorials/Termination-Resistor-500-Ohm-Non-Inductive-for-T2FD-BBTD-Rhombic-1-61-MHz-600-Watts-p136240953 Information and resources: US Army Version https://www.worldwidedx.com/threads/terminated-endfed-inverted-vee.262131/ https://forums.qrz.com/index.php?threads/terminated-end-fed-antenna-vs-efhw.716167/ https://www.dxzone.com/dx35565/tefv-terminated-end-fed-vee-antenna.html https://www.facebook.com/groups/994716810739021 https://vu3dxr.in/diy-terminated-end-fed-vee-antenna-tefv/ |
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Closest you can come to using a dummy load without using a dummy load
Not recommended but YMMV. |
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I put a random length wire up with a 9:1 balun as a temporary solution at my old place about this time last year and ran it until fall. Don't know if it was a half wave on any given band but it worked ok.
This was non terminated, FWIW. |
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Originally Posted By AnalogKid: I put a random length wire up with a 9:1 balun as a temporary solution at my old place about this time last year and ran it until fall. Don't know if it was a half wave on any given band but it worked ok. This was non terminated, FWIW. View Quote I have quite a bit of experience with end feds. I’ll be able to do an A - B comparison when I’m get the resistor. |
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Originally Posted By AnalogKid: I put a random length wire up with a 9:1 balun as a temporary solution at my old place about this time last year and ran it until fall. Don't know if it was a half wave on any given band but it worked ok. This was non terminated, FWIW. View Quote This or a 49:1 balun based EFHW is probably going to be far more efficient (relative to a terminated antenna, that is.) The main reason for terminated antennas is for radios that need extreme broadband antennas (e.g. something that band hops automatically) which isn't super applicable to ham operations. |
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I have used terminated dipoles and terminated folded dipoles. I did not know people used terminated end fed wires.
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Originally Posted By seek2: This or a 49:1 balun based EFHW is probably going to be far more efficient (relative to a terminated antenna, that is.) The main reason for terminated antennas is for radios that need extreme broadband antennas (e.g. something that band hops automatically) which isn't super applicable to ham operations. View Quote I have an excellent 80m horizontal delta loop and a pretty good EFHW-7510. They are both really good for my needs for 80, 40, and 10-20. The are both also dogshit on 60m and 160m, so the broad bandedness appeals to me, as does the potential low noise as it is a loop of sorts. Plus, I have everything but the resistor, so I get to use some shack parts. If this is a poor transmitter on 60 and 160, it might make a great receive only antenna for one of my SDR's. |
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This is...a clue - Pat_Rogers
I'm not adequately aluminumized for this thread. - gonzo_beyondo CO, MI, SC, OR - Please lobby your legislators to end discrimination against non-resident CCW permit holders |
Things I've heard are dummy loads:
1. End feds 2. Wolf River Coils 3. Anything with a trap or coil 4. Anything fed with coax instead of ladder line 5. Any antenna that is non resonant 6. Anything involving a balun or unun 7. Anything made by Chameleon 8. G5RV's (which are just a doublet, which is a well loved antenna). Tell someone you have a G5RV and you're a noob, tell them you have a home brew doublet and you're a jedi. 9. Verticals 10. Off center fed dipoles 11. Basically anything that isn't a dipole. Unless you're a tower and beam guy, then dipoles are dummy loads to you. ... ... ... 87. TEF What'd I miss? I'll let you guys know how it works. |
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Originally Posted By tyrex13: Things I've heard are dummy loads: 1. End feds 2. Wolf River Coils 3. Anything with a trap or coil 4. Anything fed with coax instead of ladder line 5. Any antenna that is non resonant 6. Anything involving a balun or unun 7. Anything made by Chameleon 8. G5RV's (which are just a doublet, which is a well loved antenna). Tell someone you have a G5RV and you're a noob, tell them you have a home brew doublet and you're a jedi. 9. Verticals 10. Off center fed dipoles 11. Basically anything that isn't a dipole. Unless you're a tower and beam guy, then dipoles are dummy loads to you. ... ... ... 87. TEF What'd I miss? I'll let you guys know how it works. View Quote I was checking out a new Barrett HF ALE antenna install on top of a building. A damn expensive dummy load with some wires tangling from it. |
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I have trapped verticals.
Loaded dipoles. A G5RV. Etc. All work well with some constraints. As an example, the G5RV is a stellar performer on its design band (20M) but don't expect miracles on 75M from one. |
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Originally Posted By AnalogKid: I have trapped verticals. Loaded dipoles. A G5RV. Etc. All work well with some constraints. As an example, the G5RV is a stellar performer on its design band (20M) but don't expect miracles on 75M from one. View Quote I have the small G5RV Jr. that I've played with some. Thing is killer on 10m at 20' in the air. There's gotta be some autist out there that has 3 160m towers with a dipole for every band installed as a flat top at 1wl... |
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Originally Posted By tyrex13: Things I've heard are dummy loads: 1. End feds 2. Wolf River Coils 3. Anything with a trap or coil 4. Anything fed with coax instead of ladder line 5. Any antenna that is non resonant 6. Anything involving a balun or unun 7. Anything made by Chameleon 8. G5RV's (which are just a doublet, which is a well loved antenna). Tell someone you have a G5RV and you're a noob, tell them you have a home brew doublet and you're a jedi. 9. Verticals 10. Off center fed dipoles 11. Basically anything that isn't a dipole. Unless you're a tower and beam guy, then dipoles are dummy loads to you. ... ... ... 87. TEF What'd I miss? I'll let you guys know how it works. View Quote Pretty much this! The best antenna for you is the one that gets you on the air! Many say my non-resonant doublet is a dummy load, but most of you have heard me on the air with a reasonably strong signal. |
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Middleofnowhere, Nebraska
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View Quote I need one. We should go borrow it like those guys that borrowed that 200' tower. |
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Originally Posted By Shootindave: I have used terminated dipoles and terminated folded dipoles. I did not know people used terminated end fed wires. View Quote Edit: Misfire. Every antenna made is a compromise. Some less than others. That said, two I would like to make are a magnetic loop, and a cobweb. |
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World ain't what it seems, is it Gunny?
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Originally Posted By Shootindave: I was checking out a new Barrett HF ALE antenna install on top of a building. A damn expensive dummy load with some wires tangling from it. View Quote View All Quotes View All Quotes Originally Posted By Shootindave: Originally Posted By tyrex13: Things I've heard are dummy loads: 1. End feds 2. Wolf River Coils 3. Anything with a trap or coil 4. Anything fed with coax instead of ladder line 5. Any antenna that is non resonant 6. Anything involving a balun or unun 7. Anything made by Chameleon 8. G5RV's (which are just a doublet, which is a well loved antenna). Tell someone you have a G5RV and you're a noob, tell them you have a home brew doublet and you're a jedi. 9. Verticals 10. Off center fed dipoles 11. Basically anything that isn't a dipole. Unless you're a tower and beam guy, then dipoles are dummy loads to you. ... ... ... 87. TEF What'd I miss? I'll let you guys know how it works. I was checking out a new Barrett HF ALE antenna install on top of a building. A damn expensive dummy load with some wires tangling from it. True broadband antennas at HF tend to be rather large affairs, so the dummy load with a wire kind of setup is not uncommon. (for mil/gov types) |
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This is...a clue - Pat_Rogers
I'm not adequately aluminumized for this thread. - gonzo_beyondo CO, MI, SC, OR - Please lobby your legislators to end discrimination against non-resident CCW permit holders |
Originally Posted By tyrex13: I need one. We should go borrow it like those guys that borrowed that 200' tower. View Quote View All Quotes View All Quotes Originally Posted By tyrex13: I need one. We should go borrow it like those guys that borrowed that 200' tower. I saw a new Toyota FJ with the Barrett mobile matching unit whip system attached at a Best Buy parking lot last year. I thought I knew who owned it, but I was wrong. Thats a lot of money to have barely attached to your vehicle. Not to mention it is basically a dummy load. |
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Originally Posted By lorazepam: Edit: Misfire. Every antenna made is a compromise. Some less than others. That said, two I would like to make are a magnetic loop, and a cobweb. View Quote I like my cobweb way more than I should. It's a lot of work to tune, like a day, but what a versatile antenna for it's footprint. Anyone with a roof or a way to get one up 20-30' should add one to their farm in my opinion. |
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Originally Posted By tyrex13: There's gotta be some autist out there that has 3 160m towers with a dipole for every band installed as a flat top at 1wl... View Quote I have space for that. And I'd make it a Five Square, with the center vertical a switchable 160/75M radiator. Closer towards center will be 4 75M quarter-waves. Designed this on paper a while back. 40-10M are covered by a Pro-96-3, which is used as the capacitance hat on the center tower. |
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Initial results are in, I'll post SWR and noise when I can. Terminated this antenna is basically less than 2:1 SWR from 160m-6m and everywhere in between.
I used a MyAntennas 9:1 unun and 140' radiating wire from them. I used a Palomar 500 ohm resistor and some 20ga wire I had laying around for the radial which runs from the resistor at the far end, down a tree and along the ground back to the unun. Antenna is about 8' at the ends and as an inverted V with the apex approximately 35' up (first throw). |
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Originally Posted By FlatlandBusa: Pretty much this! The best antenna for you is the one that gets you on the air! Many say my non-resonant doublet is a dummy load, but most of you have heard me on the air with a reasonably strong signal. View Quote There is nothing that says an antenna has to be resonant on any band. Quite the contrary is fact. |
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Looks like a dummy load.
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“Evil is powerless if the good are unafraid.” ? Ronald Reagan
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Originally Posted By K9-Bob: Looks like a dummy load. View Quote Not sure yet. S/N isn't as good as my loop and TX efficiency doesn't seem to be great on 80m. It's only a win for me if it out performs my EmComm2 on 160m. I don't get much opportunity to test on 60m, but if it works ok there that's a plus, my 80m loop and 80m EFHW don't do great on 60m. |
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Originally Posted By K9-Bob: Looks like a dummy load. View Quote Exactly. All resistor-terminated antenna topologies sacrifice efficiency for good VSWR over a broad bandwidth. Nevertheless, it can be a reasonable trade-off depending on your needs. My own case in point: when I hosted a Winlink RMS station for a few years starting back in the late naughties I wanted to offer scanning/multiband operation. Rather than build a proper fan dipole, I was lazy and put up a Radiowavz folded terminated dipole. That was all the motivation I needed to move to 500W. At 100W it really wasn't a good trade-off, but it was a great antenna at 500W. The good news was that with a tuner and a (much) more efficient antenna I learned how much better QRO is as well. It was a good learning experience and evolution for me |
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I for one am looking forward to seeing how well it works for you.
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World ain't what it seems, is it Gunny?
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I took screen shots of all the bands noise profiles before and after adding the terminating resistor and connecting radial. The termination is good for 10dB+ reduction of the noise floor. I was able to clean this noise up further by swapping in one of my AM broadcast filters.
160m unterminated Attached File 160m terminated Attached File 80m unterminated Attached File 80m terminated Attached File 60m unterminated Attached File 60m terminated Attached File 40m unterminated Attached File 40m terminated Attached File |
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Do you have solar inverters of weed grow lights near your QTH?
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“Evil is powerless if the good are unafraid.” ? Ronald Reagan
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Originally Posted By K9-Bob: Do you have solar inverters of weed grow lights near your QTH? View Quote These noise spikes are spurious emissions from local AM radio stations. I inserted an AM broadcast high pass filter. I have 2 filters. One filter filters 80m and below and that one almost completely eliminates the harmonics. The filter I used here filters 160m and below and doesn't clean it up as much. 160m with the high pass filter Attached File 80m with the high pass filter Attached File |
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The Tend Fed worked really well tonight on 160m. I was S9+10 RX and TX to Fairbanks 300 miles away from me with an S5 noise floor. The only antenna I have that I can do an A/B comparison with is a Chameleon EmComm II, so I will get that set up to do a comparison soon.
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I think you have made a resonating dummy load.
I also have no idea what I am talking about and have done no research into terminated antennas. Some additional thoughts: - good on you for doing something instead of thinking about, like 90% of people, - thanks for posting and discussing so we can learn, - do you have WSPR capability - will give you an additional data and comparison point, or maybe reverse beacon network on FT8/ CW |
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Maybe I missed it but could you please post the specifics on how you built this antenna? Wire length, orientation, etc?
I've done a lot of reading about terminated antennas, and they get a lot of hate because old ham radio operators are some of the most spiteful people around and love to get on their high horses because they're right and everybody else isn't. The Bushcomm antennas are similar construction. Quite a bit of your signal is getting launched into the ether before it makes it down to the resistor. Obviously the terminated antenna wouldn't be ideal if you or the other station are operating on a bare minimum propagation path and are on the ragged edge of being copied or not, but I'd venture to bet 99% of the time you could induce a minor efficiency loss and neither station will even notice it. |
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Originally Posted By aa777888-2: Exactly. All resistor-terminated antenna topologies sacrifice efficiency for good VSWR over a broad bandwidth. Nevertheless, it can be a reasonable trade-off depending on your needs. My own case in point: when I hosted a Winlink RMS station for a few years starting back in the late naughties I wanted to offer scanning/multiband operation. Rather than build a proper fan dipole, I was lazy and put up a Radiowavz folded terminated dipole. That was all the motivation I needed to move to 500W. At 100W it really wasn't a good trade-off, but it was a great antenna at 500W. The good news was that with a tuner and a (much) more efficient antenna I learned how much better QRO is as well. It was a good learning experience and evolution for me View Quote View All Quotes View All Quotes Originally Posted By aa777888-2: Originally Posted By K9-Bob: Looks like a dummy load. Exactly. All resistor-terminated antenna topologies sacrifice efficiency for good VSWR over a broad bandwidth. Nevertheless, it can be a reasonable trade-off depending on your needs. My own case in point: when I hosted a Winlink RMS station for a few years starting back in the late naughties I wanted to offer scanning/multiband operation. Rather than build a proper fan dipole, I was lazy and put up a Radiowavz folded terminated dipole. That was all the motivation I needed to move to 500W. At 100W it really wasn't a good trade-off, but it was a great antenna at 500W. The good news was that with a tuner and a (much) more efficient antenna I learned how much better QRO is as well. It was a good learning experience and evolution for me I picked up a new Yaesu T2FT at a hamfest for $75. It has been great for me due to the layout of my property and nothing else fitting in the available area. Something is better than nothing. |
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The devil's got my number.
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Thanks for your comments. I do have WSPR.
If you know my callsign I tested the antenna on 30m RX over the night if you want to look at WSPR map. I’d be happy to perform and post any WSPR test you’d like. |
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I used a MyAntennas 9:1 unun and 140' radiating wire from them. I used a Palomar 500 ohm resistor and some 20ga wire I had laying around for the radial which runs from the resistor at the far end, down a tree and along the ground back to the unun. Antenna is about 8' at the ends and as an inverted V with the apex approximately 35' up (first throw).
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Originally Posted By tyrex13: Thanks for your comments. I do have WSPR. If you know my callsign I tested the antenna on 30m RX over the night if you want to look at WSPR map. I'd be happy to perform and post any WSPR test you'd like. View Quote Wondering how it compares to whatever else you have at similar time, using something other than the ear test? |
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Originally Posted By tyrex13: I used a MyAntennas 9:1 unun and 140' radiating wire from them. I used a Palomar 500 ohm resistor and some 20ga wire I had laying around for the radial which runs from the resistor at the far end, down a tree and along the ground back to the unun. Antenna is about 8' at the ends and as an inverted V with the apex approximately 35' up (first throw). View Quote When you have some time, an MS Paint drawing might help me fully understand (crayon mind). Is there a specific benefit to laying that wire on the ground? The field manual drawings I have concerning what I think you are doing, leaves the return wire elevated off the ground....... I think acting as a reflector potentially? I cant find my book right now with the drawings. |
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Originally Posted By penrod72: Wondering how it compares to whatever else you have at similar time, using something other than the ear test? View Quote Interesting concept. I just set up JS8Call and am a total newb, but it appears to have a SNR function. I could make QSO's with anyone here on one antenna and then switch to the other antenna. This antenna does not appear to be as good overall as my MyAntennas EFHW-7510 and certainly not as good as my loop, BUT it is very usable on 160m and 60m. I specifically added this antenna to the farm for 160m and 60m to supplement my EFHW-7510 which doesn't do 160m at all and 60m is poor. Most guys make this antenna in a 90' version to give reasonable shortened performance on 10-80m. I think I would recommend this antenna to someone that has all of these 3 restrictions: 1. Wants an all band 80-10m or 160m-10m, but doesn't have 130' or 260' for a traditional endfed. 2. Has a local noise issue. The termination appears to knock local noise down about 10dB. 3. Doesn't have or want a tuner, want's or needs full band coverage of 80m, or 60m is important. (I think you could use this antenna on any frequency with a FT-891 or IC-718 without a tuner) This makes me think about a micro version of this antenna for portable. Maybe a ~45' radiator for 10-40m with a much smaller 9:1 and resistor for QRP or even 100w without a tuner in the field. |
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Originally Posted By Shootindave: When you have some time, an MS Paint drawing might help me fully understand (crayon mind). Is there a specific benefit to laying that wire on the ground? The field manual drawings I have concerning what I think you are doing, leaves the return wire elevated off the ground....... I think acting as a reflector potentially? I cant find my book right now with the drawings. View Quote Here's a MS Paint of my deployment. Maybe there is more efficiency by elevating the counterpoise? Mine is on the ground for ease and obstacle avoidance. I think it will still act as a reflector. When the ground thaws I will install a ground rod at both ends as recommended. Attached File Here is my parts list: Unun 140' element Resistor |
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A Half Rhombic antenna with a transformer at the feedpoint. It is going to be directional towards the resister I believe.
It would be interesting to see what would happen if you kept the "counterpoise" off the ground. Would also be interested to run an outdoor tuner instead of the 9:1. |
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Originally Posted By Shootindave: A Half Rhombic antenna with a transformer at the feedpoint. It is going to be directional towards the resister I believe. It would be interesting to see what would happen if you kept the "counterpoise" off the ground. Would also be interested to run an outdoor tuner instead of the 9:1. View Quote Ok, I have just observed some strong directivity towards the resistor in listening to a QSO on 15m between Japan and the West Coast. On the TEF I was not able to hear the West Coast Stations while I could hear them on the EF and loop. I was able to hear the Japan station stronger than the EF and loop on the TEF. Interesting and unexpected. Directivity further confirmed with another QSO observation between Japan and BC, then on my own QSO to Japan. Interestingly, my dummy load was 58-59 into the Japan station running 100w on my end, Japan station had 5 element monobander on 15 with 1kw and he was also 59 into me. I expect the directivity to only be on the upper bands. This could be very useful in establishing a link or nulling a noise. |
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Originally Posted By penrod72: I think you have made a resonating dummy load. I also have no idea what I am talking about and have done no research into terminated antennas. Some additional thoughts: - good on you for doing something instead of thinking about, like 90% of people, - thanks for posting and discussing so we can learn, - do you have WSPR capability - will give you an additional data and comparison point, or maybe reverse beacon network on FT8/ CW View Quote I ran WSPR overnight at 5 watts on 160m only. Attached File |
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I have to apologize for my "dummy load" comment - when I read the original post I read "wire and 50 ohm resistor", and not knowing anything about a terminated antenna, I thought you had lost your mind and were running some wire up a tree to a 50 ohm dummy load and it was some sort of new fangled thing. Which would have a great SWR, but...
Carry on, and I will read more carefully in the future! |
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Originally Posted By penrod72: I have to apologize for my "dummy load" comment - when I read the original post I read "wire and 50 ohm resistor", and not knowing anything about a terminated antenna, I thought you had lost your mind and were running some wire up a tree to a 50 ohm dummy load and it was some sort of new fangled thing. Which would have a great SWR, but... Carry on, and I will read more carefully in the future! View Quote All good, I like to learn and try new things. This hobby certainly keeps my mind busy and wallet empty. I was thinking of running WSPR overnight band hopping RX only, no transmit. Unless you have something else in mind? |
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I was just thinking for comparison sake (back when I thought you were nuts and putting a dummy load in a tree). My ocf dipole works great, so I bought and installed a used trap vertical. It appears to be deaf, although with good swr. When I get around to posting for help on it, I want comparative WSPR plots of same approximate times and bands to see if its just me, or possibly the vertical is working better on dx stations and I just do not hear enough on voice to notice that.
I like looking at the relative data than relying on my is what I am trying to say (even though you really cannot do everything the same at the same time without 2 wspr set ups). I figure within 30 minutes, over a few days, would give me a more scientific answer. |
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Propagation varies day to day, so WSPR can give an idea of propagation and vague antenna performance a better way would be able to do a A/B test with an antenna switch on FT8 or JS8CALL to compare signal reports.
I'm halfway through a 24 hour WSPR run on all bands TX 5W and RX that I'll post tonight. Also, Alaska HF is way different than the rest of the States HF. |
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Originally Posted By tyrex13: Things I've heard are dummy loads: 1. End feds 2. Wolf River Coils 3. Anything with a trap or coil 4. Anything fed with coax instead of ladder line 5. Any antenna that is non resonant 6. Anything involving a balun or unun 7. Anything made by Chameleon 8. G5RV's (which are just a doublet, which is a well loved antenna). Tell someone you have a G5RV and you're a noob, tell them you have a home brew doublet and you're a jedi. 9. Verticals 10. Off center fed dipoles 11. Basically anything that isn't a dipole. Unless you're a tower and beam guy, then dipoles are dummy loads to you. ... ... ... 87. TEF What'd I miss? I'll let you guys know how it works. View Quote Art WA9AWJ (SK) used to use a coax to a uhf Tee on an MJFJ dummy load with a short random wire on the other side of the Tee. He had perfect SWR and made some contacts! |
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Bad things happen in isolated instances in an armed populace, horrific things happen to a disarmed populace. 20th Century Democide https://www.hawaii.edu/powerkills/20TH.HTM
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Originally Posted By 6SJ7GT: Art WA9AWJ (SK) used to use a coax to a uhf Tee on an MJFJ dummy load with a short random wire on the other side of the Tee. He had perfect SWR and made some contacts! View Quote HFpack did an antenna shootout 20+ years ago, two of the designs were just a 75 ohm resistor across a BNC connector with a whip attached to the antenna output side. A 48" whip was down 26.3 dB from a 1/4 wave reference antenna on 20M. https://hflink.com/hfpack/antennas/shootoutvertical2002.html |
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