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Link Posted: 6/22/2023 4:52:11 PM EDT
[Last Edit: DarkLordVader] [#1]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Jambalaya:

What would be really cool is if you can use an azimuthal projection of the map centered on his QTH and filter for stations in 20 degree slices and maybe get an idea of comparative directivity based on the relative signal strength differences in different directions.

ETA if someone could automate this, it would make a great antenna comparison tool.  But I don't know enough about coding to make it happen. Which is to say, I don't know anything about coding.
View Quote
I will probably try by grid Square 2 letter prefix, it would be a lot easier and get the same answer.  Calculate Average db for the square, average difference db for same station hits, and total number of stations hit in the square.

Here is a single sample processed, I need to rerun the test and data dump probably next week so I can compare 2 samples.  My extra antenna is packed up for local field day here.

{ grid: 'EN', cnt: 163, avg_snr: -5 }
{ grid: 'EM', cnt: 143, avg_snr: -10 }
{ grid: 'FN', cnt: 132, avg_snr: -9 }
{ grid: 'DM', cnt: 105, avg_snr: -11 }
{ grid: 'CN', cnt: 65, avg_snr: -14 }
{ grid: 'EL', cnt: 58, avg_snr: -12 }
{ grid: 'DN', cnt: 37, avg_snr: -9 }
{ grid: 'FM', cnt: 35, avg_snr: -5 }
{ grid: 'CM', cnt: 27, avg_snr: -17 }
{ grid: 'JN', cnt: 10, avg_snr: -19 }
{ grid: 'DO', cnt: 9, avg_snr: -12 }
{ grid: 'IO', cnt: 6, avg_snr: -18 }
{ grid: 'FK', cnt: 6, avg_snr: -5 }
{ grid: 'JO', cnt: 4, avg_snr: -17 }
{ grid: 'IN', cnt: 4, avg_snr: -17 }
{ grid: 'BP', cnt: 4, avg_snr: -12 }
{ grid: 'EK', cnt: 4, avg_snr: -13 }
{ grid: 'KP', cnt: 4, avg_snr: -19 }
{ grid: 'IL', cnt: 3, avg_snr: -16 }
{ grid: 'PM', cnt: 3, avg_snr: -18 }
{ grid: 'CO', cnt: 2, avg_snr: -13 }
{ grid: 'JM', cnt: 2, avg_snr: -17 }
{ grid: 'HM', cnt: 2, avg_snr: -12 }
{ grid: 'FI', cnt: 2, avg_snr: -17 }
{ grid: 'KO', cnt: 2, avg_snr: -14 }
{ grid: 'PF', cnt: 2, avg_snr: -12 }
{ grid: 'QN', cnt: 1, avg_snr: -11 }
{ grid: 'BQ', cnt: 1, avg_snr: -20 }
{ grid: 'IM', cnt: 1, avg_snr: -17 }
{ grid: 'QM', cnt: 1, avg_snr: -19 }
{ grid: 'FL', cnt: 1, avg_snr: -13 }
{ grid: 'BK', cnt: 1, avg_snr: -13 }
{ grid: 'PH', cnt: 1, avg_snr: -13 }
{ grid: 'FJ', cnt: 1, avg_snr: -4 }
{ grid: 'QF', cnt: 1, avg_snr: -20 }
Total: 843

Here is another smaller one on a different day with better Euro propagation.

{ grid: 'EM', cnt: 39, avg_snr: -13 }
{ grid: 'DM', cnt: 35, avg_snr: -9 }
{ grid: 'CN', cnt: 34, avg_snr: -15 }
{ grid: 'EN', cnt: 21, avg_snr: -9 }
{ grid: 'JO', cnt: 19, avg_snr: -14 }
{ grid: 'DN', cnt: 18, avg_snr: -9 }
{ grid: 'IO', cnt: 18, avg_snr: -14 }
{ grid: 'JN', cnt: 16, avg_snr: -13 }
{ grid: 'CM', cnt: 13, avg_snr: -11 }
{ grid: 'EL', cnt: 12, avg_snr: -12 }
{ grid: 'FN', cnt: 10, avg_snr: -16 }
{ grid: 'FM', cnt: 4, avg_snr: -21 }
{ grid: 'DO', cnt: 4, avg_snr: -14 }
{ grid: 'KM', cnt: 3, avg_snr: -16 }
{ grid: 'IN', cnt: 3, avg_snr: -16 }
{ grid: 'GG', cnt: 3, avg_snr: -18 }
{ grid: 'CO', cnt: 3, avg_snr: -10 }
{ grid: 'PM', cnt: 3, avg_snr: -17 }
{ grid: 'KN', cnt: 3, avg_snr: -19 }
{ grid: 'BP', cnt: 2, avg_snr: -18 }
{ grid: 'FK', cnt: 2, avg_snr: -10 }
{ grid: 'HM', cnt: 2, avg_snr: -8 }
{ grid: 'PF', cnt: 2, avg_snr: -8 }
{ grid: 'JP', cnt: 1, avg_snr: -21 }
{ grid: 'QM', cnt: 1, avg_snr: -16 }
{ grid: 'QN', cnt: 1, avg_snr: -15 }
{ grid: 'FJ', cnt: 1, avg_snr: -19 }
{ grid: 'KP', cnt: 1, avg_snr: -17 }
{ grid: 'EK', cnt: 1, avg_snr: -17 }
{ grid: 'FF', cnt: 1, avg_snr: -17 }
{ grid: 'IM', cnt: 1, avg_snr: -18 }
Total: 277


Link Posted: 6/22/2023 8:44:47 PM EDT
[#2]
Some could call it a project, others maybe not

I applied for my late (sk 2/20/23) fathers callsign that he held for 20+ years, and his father had it for an unknown amount of time before that.

Well the fcc got all fubar'd for a few weeks and today they approved it finally just in time for field day. It'll be my first field day that I've participated in after getting back into radio and I get to use a call that means so much to me. See you guys out there on the air
Link Posted: 6/22/2023 8:50:52 PM EDT
[Last Edit: seek2] [#3]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By DarkLordVader:
I will probably try by grid Square 2 letter prefix, it would be a lot easier and get the same answer.  Calculate Average db for the square, average difference db for same station hits, and total number of stations hit in the square.

Here is a single sample processed, I need to rerun the test and data dump probably next week so I can compare 2 samples.  My extra antenna is packed up for local field day here.

data snipped
View Quote


I'd do median db per grid rather than average, you're more likely to have lucky paths or superior stations in the more populated grid squares that will skew an average higher, median will fix that and in less populated grid squares will devolve to an average anyway.


ETA:
Based on the first data set it looks like you have directivity to the SSE and NW -- if you were using a horizontal
antenna I would guess the wire ran roughly from SW to NE.
Link Posted: 6/22/2023 9:53:39 PM EDT
[Last Edit: DarkLordVader] [#4]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By seek2:


I'd do median db per grid rather than average, you're more likely to have lucky paths or superior stations in the more populated grid squares that will skew an average higher, median will fix that and in less populated grid squares will devolve to an average anyway.


ETA:
Based on the first data set it looks like you have directivity to the SSE and NW -- if you were using a horizontal
antenna I would guess the wire ran roughly from SW to NE.
View Quote
I agree on the median. And that antenna does face NE. Horiz dipole.  Probably 0.6+ wavelengths in height.  Should have broadside and some low angle squirts on the poles. Throw in a westerly tilt to upwards to 0.7 wavelengths and who knows.
Attachment Attached File

Link Posted: 6/23/2023 10:26:02 PM EDT
[#5]
I need a USB powered fan to sit under my Inovato Quandra to keep it from shutting its self down. I think it is over heating.

Anyone have a Amazon link for one known to not cause RF noise?
Link Posted: 6/24/2023 7:48:21 PM EDT
[#6]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shootindave:
I need a USB powered fan to sit under my Inovato Quandra to keep it from shutting its self down. I think it is over heating.

Anyone have a Amazon link for one known to not cause RF noise?
View Quote

I use one of these under my G90 when doing digital modes. Doesn't seem to cause any interference.  
MissingImage
Failed To Load Product Data

Link Posted: 6/25/2023 10:44:21 AM EDT
[#7]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shootindave:
I need a USB powered fan to sit under my Inovato Quandra to keep it from shutting its self down. I think it is over heating.

Anyone have an Amazon link for one known to not cause RF noise?
View Quote
@Shootindave

Don't know if you have access to a 3D printer but here is a fan stand someone made. Note in the comments about lack of thermal paste etc. Might find more options on other 3D file sights as well, search for T95 stand/cooler/fan etc.
Fan stand
Link Posted: 6/25/2023 6:56:23 PM EDT
[#8]
Attachment Attached File


Gonna try to get my OCFD up today for evaluation
Link Posted: 6/25/2023 8:05:45 PM EDT
[#9]
Installed a new hf antenna on my truck…naturally this meant modifying parts in order to make it work
Attachment Attached File

Attachment Attached File


Icom ah-2b with tuning duties handles by a icom ah-4…fed from an icom ic7000
Link Posted: 6/27/2023 2:24:00 PM EDT
[#10]
The Buckmaster OCFD came down the same day it went up. Tuned fine, it was just too noisy running over the house. Since this antenna wasn't going to remain in the fleet I decided to stop putting up my loop. I've got the feed point up a 30' fiberglass pole currently, going to push that up to 40' when I'm done trimming. I've got the corners of the horizontal delta loop up at about 40'.

I do need to get one more pully up to take out some tension/droop. Does anybody know of an all plastic pully that is a "slide on" so I don't have to pull the wire halfway out? I want to put the tension pulley in between the 2 corners pulleys.



Link Posted: 6/27/2023 2:34:28 PM EDT
[#11]
While amazon does have plastic pulleys that can be disassembled and reassembled around the line
( look here ) I think I'd be inclined to use a metal split pulley with a non-conductive support line.

Those are really common for rope work, something like this one will support more tension and last way longer.

Something that's a few square inches of metal isn't going to have any impact on an antenna for a wavelength that's hundreds of times that size.
Link Posted: 6/27/2023 5:04:29 PM EDT
[Last Edit: nikdfish] [#12]
Originally Posted By tyrex13:
The Buckmaster OCFD came down the same day it went up. Tuned fine, it was just too noisy running over the house. Since this antenna wasn't going to remain in the fleet I decided to stop putting up my loop. I've got the feed point up a 30' fiberglass pole currently, going to push that up to 40' when I'm done trimming. I've got the corners of the horizontal delta loop up at about 40'.

I do need to get one more pully up to take out some tension/droop. Does anybody know of an all plastic pully that is a "slide on" so I don't have to pull the wire halfway out? I want to put the tension pulley in between the 2 corners pulleys.



View Quote



If you have access to a 3d printer, I put these together a while back.  Printed in PETG  or better yet ASA, they should hold up to UV. I used them as corner pulleys for a 14 awg  160m FWL.
https://www.printables.com/model/437051-wire-antenna-corner-pulleys
Link Posted: 6/27/2023 8:49:14 PM EDT
[#13]
Attachment Attached File


Where did you get the black mount for the antenna?
Link Posted: 6/27/2023 11:25:09 PM EDT
[#14]
So yesterday I went out and tried messing with my 6BTV again.  I have 30m in a good place.  But 40m is resonant a little low, so SWR climbs over 3:1 as you approach 7.300.  The trouble is, there is no 40m trap to adjust, just the big 80m coil/trap assembly that can't be tuned.

The only way to tune 40m is by shortening the tube between the 30m trap and the 80m coil assembly.  But I've run out of room there.

It's worth noting that 40m does radiate on all of the antenna sections below the 80m assembly.  So I could potentially shorten some of those other sections of the antenna, but would then need to compensate by making more trap adjustments.

Alternatively, DX Engineering makes a shunt coil that is supposed to make the antenna a better match on 40 and 80 without affecting the higher frequencies.  This might bring the curve lower and get that end of the band inside the range of my internal tuner.

Of course, the right and proper way to do it would be to measure the antenna and calculate the size coil I would need, then make one.
Link Posted: 6/28/2023 4:15:31 AM EDT
[#15]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By K9-Bob:
https://www.ar15.com/media/mediaFiles/54857/IMG_6881_jpeg-2863770_jpg-2865970.JPG

Where did you get the black mount for the antenna?
View Quote


Yodateq
Yodateq
Link Posted: 6/29/2023 3:55:04 AM EDT
[#16]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By fosters:


Yodateq
Yodateq
View Quote



I have a 2020 Jeep Grand Cherokee and can't find a mount for my Little Tarheel II.
Link Posted: 7/4/2023 11:29:40 PM EDT
[#17]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By fosters:


Yodateq
Yodateq
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By fosters:
Originally Posted By K9-Bob:
https://www.ar15.com/media/mediaFiles/54857/IMG_6881_jpeg-2863770_jpg-2865970.JPG

Where did you get the black mount for the antenna?


Yodateq
Yodateq


Their prices are nuts.
Link Posted: 7/9/2023 11:21:24 AM EDT
[#18]
End Fed Half Wave kit being built, to replace (and then will steal ideas) to improve my homebrew one.
Link Posted: 7/10/2023 7:30:45 PM EDT
[#19]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By penrod72:
End Fed Half Wave kit being built, to replace (and then will steal ideas) to improve my homebrew one.
View Quote

I have 5 49:1 transformers sitting here. Not sure what I will do with them.
Link Posted: 7/13/2023 4:47:38 PM EDT
[Last Edit: WillieTangoFox] [#20]
The nice thing about old work trucks is you can run wood screws into the dash without any regrets. :-)

LIDO HT mount. Got all my Frequ including AM airband and such programmed into the UV-5K.

Need a cig lighter USB port thingy for charging. Will get at wal mart this weekend .

Attachment Attached File
Link Posted: 7/13/2023 7:30:48 PM EDT
[#21]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shootindave:
The nice thing about old work trucks is you can run wood screws into the dash without any regrets. :-)

LIDO HT mount. Got all my Frequ including AM airband and such programmed into the UV-5K.

Need a cig lighter USB port thingy for charging. Will get at wal mart this weekend .

https://www.ar15.com/media/mediaFiles/123862/IMG_4322_jpeg-2884564.JPG
View Quote

And that usb port thingy will create so much rfi you’ll wanna throw it out the window at 60mph
Link Posted: 7/16/2023 5:58:45 PM EDT
[#22]
Attempted and failed the K6ARK antenna kit.

I am not able to build things with tiny parts. Glad I tried.
Link Posted: 7/16/2023 8:22:14 PM EDT
[#23]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shootindave:
Attempted and failed the K6ARK antenna kit.

I am not able to build things with tiny parts. Glad I tried.
View Quote
It's not easy that's for sure. I'm gonna try again now that I have a better soldering iron.
Link Posted: 7/17/2023 9:03:40 PM EDT
[#24]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shootindave:
Attempted and failed the K6ARK antenna kit.

I am not able to build things with tiny parts. Glad I tried.
View Quote


Send it down here to me in Branson. I will fix it.
Link Posted: 7/17/2023 9:13:21 PM EDT
[#25]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shootindave:
Attempted and failed the K6ARK antenna kit.

I am not able to build things with tiny parts. Glad I tried.
View Quote

Flux is your friend. My hand shake like a dog shitting a peach pit if I even get close to a soldering iron. Flux and good solder make a big difference. Lead free solder sucks.
Link Posted: 7/18/2023 7:20:16 PM EDT
[#26]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By lorazepam:

Flux is your friend. My hand shake like a dog shitting a peach pit if I even get close to a soldering iron. Flux and good solder make a big difference. Lead free solder sucks.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By lorazepam:
Originally Posted By Shootindave:
Attempted and failed the K6ARK antenna kit.

I am not able to build things with tiny parts. Glad I tried.

Flux is your friend. My hand shake like a dog shitting a peach pit if I even get close to a soldering iron. Flux and good solder make a big difference. Lead free solder sucks.



Yes, Lead free solder sucks, bigtime. I have been soldering for about 55 years, and I would like to think I am still pretty good at it. But I can't solder anything with lead free solder. The crap is worthless.
Link Posted: 7/20/2023 6:15:26 PM EDT
[#27]
Well today I am experiencing a power outage right now.  

I hooked up my LiFePO4 battery to my radio and like magic, my S7 noise on 40 meters is down around S1 instead. The noise floor on 20 meters isn't even registering.  

I hope the noise source is coming from my own home and I hope it's something non-critical and easily replaced with an RF quiet alternative.
Link Posted: 7/20/2023 7:13:19 PM EDT
[#28]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Jambalaya:
Well today I am experiencing a power outage right now.  

I hooked up my LiFePO4 battery to my radio and like magic, my S7 noise on 40 meters is down around S1 instead. The noise floor on 20 meters isn't even registering.  

I hope the noise source is coming from my own home and I hope it's something non-critical and easily replaced with an RF quiet alternative.
View Quote


Go ahead and pop the panel breaker yourself and then see if the floor suddenly jumps up when your neighbor's power comes back on.
Link Posted: 8/28/2023 8:20:14 AM EDT
[#29]
Going to have to do some hurricane preps. In the meantime I ordered a HermesLite-2.
Link Posted: 8/28/2023 2:12:55 PM EDT
[#30]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By seek2:


Go ahead and pop the panel breaker yourself and then see if the floor suddenly jumps up when your neighbor's power comes back on.
View Quote

Funny thing.  I went and labeled all my breakers, and with them all back on and all the lights on, noise floor on 40 was like S1 or S2 during the day.

At night it's back up to S7.  I think much of it might just be natural noise.  If it's from fluorescent or LED lighting, it's not coming from my house because I had everything turned on. So at least I know I have done everything I can here without going around the neighborhood on a hunt.
Link Posted: 8/29/2023 10:59:24 AM EDT
[#31]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By CS223:
Going to have to do some hurricane preps. In the meantime I ordered a HermesLite-2.
View Quote

That's a great piece of hardware, especially when used with Thetis software.

Unfortunately the HL2 receiver is only a 12-bit ADC. The TRX-Duo is far superior, with dual 16-bit ADCs, and can also run with Thetis software. The downside is that the RF output of the TRX-Duo is only 25mW, so it requires an amp kit of some kind to be useful as a full transciever.
Link Posted: 8/29/2023 1:57:44 PM EDT
[#32]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By aa777888-2:

That's a great piece of hardware, especially when used with Thetis software.

Unfortunately the HL2 receiver is only a 12-bit ADC. The TRX-Duo is far superior, with dual 16-bit ADCs, and can also run with Thetis software. The downside is that the RF output of the TRX-Duo is only 25mW, so it requires an amp kit of some kind to be useful as a full transciever.
View Quote
Thetis and PureSignal is what got me interested. I figured I could dip my toe into the Anan waters without spending a fortune. I also have an RSP1A & I had two Softrocks that I built but I sold them as they were a little cumbersome. Assuming I find it to my liking maybe I can either find a deal on a HR50 amp or get one one the little chicom 50W amps to drive my 87A.
Link Posted: 8/29/2023 2:03:57 PM EDT
[#33]
You are going to love it!
Link Posted: 8/30/2023 9:15:48 AM EDT
[Last Edit: Mach] [#34]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By CS223:
Thetis and PureSignal is what got me interested. I figured I could dip my toe into the Anan waters without spending a fortune. I also have an RSP1A & I had two Softrocks that I built but I sold them as they were a little cumbersome. Assuming I find it to my liking maybe I can either find a deal on a HR50 amp or get one one the little chicom 50W amps to drive my 87A.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By CS223:
Originally Posted By aa777888-2:

That's a great piece of hardware, especially when used with Thetis software.

Unfortunately the HL2 receiver is only a 12-bit ADC. The TRX-Duo is far superior, with dual 16-bit ADCs, and can also run with Thetis software. The downside is that the RF output of the TRX-Duo is only 25mW, so it requires an amp kit of some kind to be useful as a full transciever.
Thetis and PureSignal is what got me interested. I figured I could dip my toe into the Anan waters without spending a fortune. I also have an RSP1A & I had two Softrocks that I built but I sold them as they were a little cumbersome. Assuming I find it to my liking maybe I can either find a deal on a HR50 amp or get one one the little chicom 50W amps to drive my 87A.


You will never look back.

Thetis and pure signal are magic.
Link Posted: 8/30/2023 8:14:50 PM EDT
[Last Edit: Harlikwin] [#35]
26 out  of 50 states so far with this... Given its limits thats pretty good, but I don't think I'll get many more without an Upgrayyyde.

Link Posted: 8/30/2023 11:54:16 PM EDT
[#36]
I made a quarter wave 20m vertical antenna with speaker wire and a binding post today. Works Great!
Link Posted: 9/3/2023 12:33:13 AM EDT
[#37]
I got my GP-6 back up today. Ice brought it down in the spring. Mast is a 20’ stick of 2” aluminum tubing with 1/8” wall. Should be strong enough. It’s a heck of a lot lighter to put up than the 1.5” and 1.25” EMT that I had bolted together for a previous mast. Base of the mast is at ~10’, so feedpoint at about 30’.

Attachment Attached File


Attachment Attached File


Also permanently installing a roll up J pole for backup 2m/70cm. Feedpoint will be at about 40’. Pole is a 46’ DX Engineering fiberglass mast. Top 2 sections are too skinny to support the feed point for my horizontal delta loop, so the loop feedpoint will attach to a guy ring 2 sections down from the top.

Attachment Attached File


Attachment Attached File
Link Posted: 9/11/2023 8:55:28 PM EDT
[#38]
So I made a 9:1 transformer and I didn't have a box to put it in. I was at Walmart and found a four space plastic box for a dollar in the crafts department.
Attachment Attached File

I figured I would give it a shot and see how it works. It will never see more than 40w, and I don't intend for it to be a permanent install.
I don't have any silicone to glue it down so that will be next trip. Good enough to see how it works.
Attachment Attached File

Depending on the length of the wire, I may be able to store it and a counterpoise in the box.
Attachment Attached File
Link Posted: 9/11/2023 9:22:07 PM EDT
[#39]
nice
Link Posted: 9/11/2023 10:13:56 PM EDT
[#40]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By lorazepam:
So I made a 9:1 transformer and I didn't have a box to put it in. I was at Walmart and found a four space plastic box for a dollar in the crafts department.
https://www.ar15.com/media/mediaFiles/242375/IMG_20230911_192532821_jpg-2950533.JPG
I figured I would give it a shot and see how it works. It will never see more than 40w, and I don't intend for it to be a permanent install.
I don't have any silicone to glue it down so that will be next trip. Good enough to see how it works.
https://www.ar15.com/media/mediaFiles/242375/IMG_20230911_192544187_jpg-2950545.JPG
Depending on the length of the wire, I may be able to store it and a counterpoise in the box.
https://www.ar15.com/media/mediaFiles/242375/IMG_20230911_192625053_jpg-2950549.JPG
View Quote

You could put a common mode choke in the other half.  I've seen some commercial manufacturers that double up on transformers in the same housing this way.
Link Posted: 9/11/2023 11:20:40 PM EDT
[#41]
I think it would be a tight fit. The latch mechanism takes up space, and having room for connections. I have some space I could gain. I have another box.
Link Posted: 9/11/2023 11:32:27 PM EDT
[Last Edit: Gamma762] [#42]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Jambalaya:
So yesterday I went out and tried messing with my 6BTV again.  I have 30m in a good place.  But 40m is resonant a little low, so SWR climbs over 3:1 as you approach 7.300.  The trouble is, there is no 40m trap to adjust, just the big 80m coil/trap assembly that can't be tuned.

The only way to tune 40m is by shortening the tube between the 30m trap and the 80m coil assembly.  But I've run out of room there.

It's worth noting that 40m does radiate on all of the antenna sections below the 80m assembly.  So I could potentially shorten some of those other sections of the antenna, but would then need to compensate by making more trap adjustments.

Alternatively, DX Engineering makes a shunt coil that is supposed to make the antenna a better match on 40 and 80 without affecting the higher frequencies.  This might bring the curve lower and get that end of the band inside the range of my internal tuner.

Of course, the right and proper way to do it would be to measure the antenna and calculate the size coil I would need, then make one.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Jambalaya:
So yesterday I went out and tried messing with my 6BTV again.  I have 30m in a good place.  But 40m is resonant a little low, so SWR climbs over 3:1 as you approach 7.300.  The trouble is, there is no 40m trap to adjust, just the big 80m coil/trap assembly that can't be tuned.

The only way to tune 40m is by shortening the tube between the 30m trap and the 80m coil assembly.  But I've run out of room there.

It's worth noting that 40m does radiate on all of the antenna sections below the 80m assembly.  So I could potentially shorten some of those other sections of the antenna, but would then need to compensate by making more trap adjustments.

Alternatively, DX Engineering makes a shunt coil that is supposed to make the antenna a better match on 40 and 80 without affecting the higher frequencies.  This might bring the curve lower and get that end of the band inside the range of my internal tuner.

Of course, the right and proper way to do it would be to measure the antenna and calculate the size coil I would need, then make one.

What are you using for radials? Adding some tuned 40m radials would likely move the resonance a little.

ETA: I see on a previous page it looks like you installed a bunch of 33 foot radials... try adding a few about 20~21 feet long and see what happens with your 40 meters.

Originally Posted By Jambalaya:
Originally Posted By seek2:


Go ahead and pop the panel breaker yourself and then see if the floor suddenly jumps up when your neighbor's power comes back on.

Funny thing.  I went and labeled all my breakers, and with them all back on and all the lights on, noise floor on 40 was like S1 or S2 during the day.

At night it's back up to S7.  I think much of it might just be natural noise.  If it's from fluorescent or LED lighting, it's not coming from my house because I had everything turned on. So at least I know I have done everything I can here without going around the neighborhood on a hunt.

Neighbors have a plasma TV or something similar might be a good guess. Do you have streetlights? Bad ballast or noisy LED driver.
Link Posted: 9/12/2023 1:04:47 AM EDT
[#43]
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Originally Posted By Gamma762:

What are you using for radials? Adding some tuned 40m radials would likely move the resonance a little.

ETA: I see on a previous page it looks like you installed a bunch of 33 foot radials... try adding a few about 20~21 feet long and see what happens with your 40 meters.


Neighbors have a plasma TV or something similar might be a good guess. Do you have streetlights? Bad ballast or noisy LED driver.
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There are streetlights farther down the road.  I wouldn't be surprised about a plasma TV.  I don't think it's anything in my home since I turned on all the lights during the day a few weeks back and the noise on 40m was S2.  If it is a TV, it probably won't be on late night after most people go to bed, so that might be another way to narrow it down.  If it's a streetlight it would be on until dawn.

Having written this, it's 11:00pm in my time zone and I am seeing S1 noise floor and occasional static crashes on 40m.  I can live with that.  So whatever the noise source is, it's definitely someone using some electronics between sundown and bedtime.

For radials I am using 14 gauge stranded copper THHN.  I can try adding some more at the 20-21 foot length to see what happens.  I did end up adding a shunt coil and it got the SWR lower at the lowest point of the dip. But if a few shorter radials would help scoot the resonance up in frequency a little on 40m, it would be worth trying.  That said, these are ground radials stapled down to the surface andI thought length didn't matter much unless they are elevated.  But I have pretty poor soil.  
Link Posted: 9/12/2023 12:30:43 PM EDT
[Last Edit: lorazepam] [#44]
Ok, here is version 1.1
Attachment Attached File

I am going to cut a wire and give it a shot. If it works I will silicone it all in place and use it. If not, try something else.
Link Posted: 9/12/2023 5:15:42 PM EDT
[#45]
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Originally Posted By Jambalaya:

There are streetlights farther down the road.  I wouldn't be surprised about a plasma TV.  I don't think it's anything in my home since I turned on all the lights during the day a few weeks back and the noise on 40m was S2.  If it is a TV, it probably won't be on late night after most people go to bed, so that might be another way to narrow it down.  If it's a streetlight it would be on until dawn.

Having written this, it's 11:00pm in my time zone and I am seeing S1 noise floor and occasional static crashes on 40m.  I can live with that.  So whatever the noise source is, it's definitely someone using some electronics between sundown and bedtime.

For radials I am using 14 gauge stranded copper THHN.  I can try adding some more at the 20-21 foot length to see what happens.  I did end up adding a shunt coil and it got the SWR lower at the lowest point of the dip. But if a few shorter radials would help scoot the resonance up in frequency a little on 40m, it would be worth trying.  That said, these are ground radials stapled down to the surface andI thought length didn't matter much unless they are elevated.  But I have pretty poor soil.  
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This guy has been playing with them for years, I think he has a handle on them.
3 Rules - Quick Tip - Radials for Ground Mounted Vertical Antennas
Link Posted: 9/12/2023 6:38:33 PM EDT
[#46]
I put up a 41' wire with a 17' counterpoise, and 40 is around 5:1, 20, 17, and 15 are under 1.5 and 12 and 10 are under 2.5. This is a pretty cool antenna. I will check different wire lengths and see what I get.
Link Posted: 9/12/2023 7:42:33 PM EDT
[#47]
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Originally Posted By 4HShooter:
Some could call it a project, others maybe not

I applied for my late (sk 2/20/23) fathers callsign that he held for 20+ years, and his father had it for an unknown amount of time before that.

Well the fcc got all fubar'd for a few weeks and today they approved it finally just in time for field day. It'll be my first field day that I've participated in after getting back into radio and I get to use a call that means so much to me. See you guys out there on the air
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Very cool. Maybe my son will have my call someday.
Link Posted: 9/12/2023 9:35:39 PM EDT
[#48]
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Originally Posted By lorazepam:
Ok, here is version 1.1
https://www.ar15.com/media/mediaFiles/242375/IMG_20230912_112000030_jpg-2951043.JPG
I am going to cut a wire and give it a shot. If it works I will silicone it all in place and use it. If not, try something else.
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Ah nice!
Link Posted: 9/12/2023 9:36:52 PM EDT
[#49]
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Originally Posted By lorazepam:
I put up a 41' wire with a 17' counterpoise, and 40 is around 5:1, 20, 17, and 15 are under 1.5 and 12 and 10 are under 2.5. This is a pretty cool antenna. I will check different wire lengths and see what I get.
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Those 9:1 usually work well with an internal tuner.
Link Posted: 9/12/2023 9:40:16 PM EDT
[Last Edit: lorazepam] [#50]
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Originally Posted By Jambalaya:

Those 9:1 usually work well with an internal tuner.
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Originally Posted By Jambalaya:
Originally Posted By lorazepam:
I put up a 41' wire with a 17' counterpoise, and 40 is around 5:1, 20, 17, and 15 are under 1.5 and 12 and 10 are under 2.5. This is a pretty cool antenna. I will check different wire lengths and see what I get.

Those 9:1 usually work well with an internal tuner.

The 6100 and G90 should be able to handle it. Not very efficient at 40 though. 12 and 10 will be no issue. This was a fun project, I wasn't sure if the box would handle it, and I am pleasantly surprised.
Edit: I won't need a tuner on 20, 17, 15m.
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