The AM Forum
March 28, 2024, 08:43:29 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1] 2   Go Down
  Print  
Author Topic: Folded Unipole Antenna  (Read 7896 times)
0 Members and 1 Guest are viewing this topic.
kc4mne
Member

Offline Offline

Posts: 18


« on: November 25, 2019, 10:54:56 PM »

Hello

Would like to add a "folded uipole", maybe "dual band shortened folded unipole" would be a better description to use on 80M and 160M. My tower is 70' tall. However have not found much on measurements online. Any ideas?  I have space for some ground radials, but not a perfect circle of radials around the tower.
Logged
W1ITT
Member

Offline Offline

Posts: 573


« Reply #1 on: November 26, 2019, 09:25:31 AM »

Get yourself a copy of Low Band DXing, by ON4UN, published by ARRL.  It's $45 but one of the best practical antenna books they have put out. In chapter 9, fifth edition , starting at about 9.62, John gets into the practicalities of just what you are attempting, and has interesting solutions for 160m as well as 80m.  If you have some good wide spaced or vacuum capacitors, the gamma and omega match configurations will allow you to do what you need to do.
For a ground system, consider using galvanized fence wire laid out on the ground.  Rob Sherwood at  www.sherweng.com  reprints an article he wrote years ago in Ham Radio Magazine with good measurements.  I use some screen under my 160m Tee, and there's a fellow on Ebay selling pvc coated galvanized chicken wire, 150 feet by one foot wide for $75.  I might add a bit of that to my own system for winter 160m use, then roll it up in the spring when I have to mow the lawn.
73 de Norm W1ITT
Logged
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #2 on: November 26, 2019, 09:04:56 PM »

Below in PDF 1 is a typical "Folded UniPole" we use for broadcasting and it can be applied to almost any short antenna or any antenna less than 0.223 Lambda. The tower structure itself is fully grounded at the base to the radial field ring.

Lambda = 1 Wavelength.

Here is the problem in attempting to use it on two different frequencies: You will notice the item pointed out as "Impedance Matching Connection."

This is a short from the tower to the skirt at a specified point (height) in order to match the impedance at the specified frequency down at the feed-ring.

For 3.7 MHz, 1/4 Lambda is 67 feet so your tower is just over a quarter wave.

You could use a Slant Feed for 80m where a slant wire from your tuner output hits a point at the tower for about a 50 ohm impedance. See PDF 2.

Your tower is 0.135 Lambda at 1.9 MHz where at 1.9 MHz a quarter wave is 130  feet. A true folded unipole could be used but much experimentation and or computation would have to be done to find the "Impedance Matching Connection" point.
 

Phil - AC0OB

* Folded Unipole Broadcast Installation.pdf (36 KB - downloaded 189 times.)
* Slant wire Dawson_Slant_Wire_Shunt_Fed_IEEE_BTS_2010.pdf (895.36 KB - downloaded 309 times.)
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
kb2vxa
Member

Offline Offline

Posts: 162


I modulate, therefore AM


« Reply #3 on: November 28, 2019, 11:13:06 AM »

To keep it simple and the Greek alphabet out of it, use the standard design with 3 skirt wires spaced 18" from each tower leg and the upper commoning ring connected to the tower at the 60ft level. Don't forget to use Kevlar guys or steel broken into non-resonant lengths with porcelain egg insulators like you see on power poles and broadcast towers. If you use plain steel rope you'll wonder where the watts went. That's ideal for 160M and you'll find it has a low takeoff angle on 80-75M for great DX. Of course you'll need an ATU at the tower base, I'd use an automatic, weatherproof unit because remotely controlled units that were used on ship to shore shore stations are hard to find. That antenna can be used on 40M also but tuning gets a bit sharp, on 20M too sharp to be practical. You can use a broadcast engineer's trick to extend radials past structures on the property. Ring them with copper, solder the radials to it, and extend them on the far side to the edge of the property. They work best on the surface, but with copper thieves running around with cutting tools these days it's second best to bury them a couple of inches in slit trenches. You probably would shy away from the 120 radial system around AM broadcast towers, copper is way too expensive these days, but the more the merrier. Don't expect this to be a cheap antenna project, it isn't.

Take my word for it, the vertical folded unipole is fantastic on the low frequency bands having been adapted from AM broadcast use. I've seen a few used mostly to save expensive steel, the tower is a bit shorter than a series fed quarter wave AND it has a lower vertical radiation angle that increases a station's coverage watt for watt. K2PG Phil has them, one at his Pennsylvania QTH for his re-tuned AM broadcast transmitter, a 10KW Collins unit BTW, (;->) topped with a 2M vertical and center support for his dipole. I used the one at his West Creek, NJ QTH topped with an HF tri-band beam, 6M and 2M horizontal beams, the center support for a 160M open delta, and a 4 element 2M vertical folded dipole array. The tower may be used in the usual ways, side mount antennas become part of the tower and antennas above the top commoning ring are ignored by the RF when all coax lines come to the bottom and are grounded to the tower. 80M DX was absolutely fantastic, I had a 5 & 9 both ways QSO with England using only 100W PEP SSB while the dipole kilowatt guys pulled their hair out having no signal across the big pond.
Logged

73 de Warren KB2VXA
Station powered by atomic energy, operator powered by natural gas.
W1ITT
Member

Offline Offline

Posts: 573


« Reply #4 on: November 28, 2019, 12:22:18 PM »

Warren..    The modern automatic antenna matchers that I'm aware of are all Pi networks.  Like it or not, the Greek alphabet is going to be involved.    I suspect that the power ratings of the common ham radio ATUs  are optimistic at best, especially for AM use.  But if one has the extra drachmas to spend, there are some cool units out there.
73 de Norm W1ITT
Logged
kb2vxa
Member

Offline Offline

Posts: 162


I modulate, therefore AM


« Reply #5 on: December 01, 2019, 01:08:35 PM »

Hi Norm,

"The modern automatic antenna matchers that I'm aware of are all Pi networks.  Like it or not, the Greek alphabet is going to be involved."
Like Fred Flintstone (not flintstone mop) said, droll, very droll. On 14 March do you bake a Pi pie? On Einstein's birthday they virtually take over Princeton, NJ. BTW Raspberry Pi is not edible.

You're right and I wasn't covering all the bases, the automatic ATUs that go with 100W PEP mobile rice burners are meant to tune a 102" CB whip. Considering a typical AM/CW boat anchor puts out 100-140W carrier depending on the make, model, and band they'd hold up well under the 20% CW duty cycle, but hit one with 200-280W P-P AM and likely the magic smoke would waft skyward. Then there's today's elevated noise floor making a 600W output pretty much necessary to be heard well and forget it. One of my Frankenstein Laboratories BMF ATUs made out of 10KW AM transmitter parts would hold up well, but that would mean a trip to the dog house for every frequency change, most unpleasant in stormy weather.

I mentioned remotely controlled ATUs from defunct shore stations because Phil K2PG used one to tune his grounded vertical folded unipole in West Creek. His Pennsylvania unit is fixed tuned, a modified broadcast unit to handle the 10KW Collins 21E before the 480V 3 phase power pole rotted and fell, weather tight steel cabinet, ceramic tits and all. I remember the day when he blew up the West Creek one with a Collins 20V, bits of ceramic doorknobs all over the bottom of the cabinet. I'm no EE so I had to take my best guess, they were all 4.5KV caps and he had a bunch in the parts inventory, I used several smaller values to replace the larger ones thus distributing the circulating RF current and heat. Then out came the MFJ antenna analyzer and screwdriver to re-tune the whirring and clicking wee beastie.



* K2PG PA Cottage.jpg (294.74 KB, 640x480 - viewed 318 times.)
Logged

73 de Warren KB2VXA
Station powered by atomic energy, operator powered by natural gas.
W1ITT
Member

Offline Offline

Posts: 573


« Reply #6 on: December 01, 2019, 02:36:11 PM »

Warren..  Not necessarily just for use on March 14, but I do have a ceramic pie plate with the numerical value of pi worked out to a whole string of digits around the perimeter and a big pi symbol in the bottom of it.  It was given to me by a good friend who seemed to think I might have been a nerd at some point in my life.
Unless one is a QSY everywhere guy, most of us have just a couple different watering holes that we frequent on the bands, so a relay setup with a couple different tuning solutions might be handy,  I did that once for phone/cw switching on an 80m vertical.  I have one tuner that requires about a 500 foot hike out to the doghouse in the woods.  Here in Maine in winter, it's either snowshoes across three feet of snow or just live with that part of the band until spring.
I figure I can use the physical exercise, so I tend to avoid the store bought solutions, and I have plenty of Ls and Cs around so I brew my own tuners.  But a bulletproof 5kw autotuner would be a thing of beauty...  The government sites that I have seen all seem to favor broadband antennas and fixed matching.  Autotuning seems mostly to be on aircraft and ships.
73 de Norm W1ITT
Logged
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #7 on: December 01, 2019, 04:45:01 PM »

Hello

Would like to add a "folded uipole", maybe "dual band shortened folded unipole" would be a better description to use on 80M and 160M. My tower is 70' tall. However have not found much on measurements online. Any ideas?  I have space for some ground radials, but not a perfect circle of radials around the tower.

Ok, here is the best I can do for now for a 70 ft. tall triangular metallic tower with a 1 ft. face for 1.9 MHz.

This was scaled from one of our broadcast towers.

The impedance matching point is calculated to be about 33 feet above ground with an 18 inch spacing of the three #12 insulated wires from the tower. The impedance matching point here also serves as the "spreader" to keep the wires parallel along the length of the face of the tower.

You may have to experiment as to the exact shunt impedance matching point height and before you affix cross (spreader) arms at that point.

The feed-point HOOP needs to have insulated cables with insulated spacers and a turnbuckle below it in order to tension it and to keep the 3 skirt wires taught. The three tensioner cables need to be spaced 120 degrees apart.

The diagram shows the dimensions.


Phil - AC0OB

 

* Folded Unipole for ARS.pdf (133.68 KB - downloaded 159 times.)
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
Jim, W5JO
Member

Offline Offline

Posts: 2506


« Reply #8 on: December 01, 2019, 08:04:16 PM »

As I recall the MFJ-998RT, and maybe the LDG 1000, remote tuners are L network designs.  I read that the MFJ is but not the LDG. 

The MFJ has an output for coax or single wire.
Logged
kc4mne
Member

Offline Offline

Posts: 18


« Reply #9 on: December 09, 2019, 10:14:59 PM »

Thanks for all the ideas
AC0OB, what would the dimensions be for the 80 M version. Also the 70' tower is close to a building so the skirt wires can only be 12" away from the corners of the tower. Tuner not be a problem, will be L fixed on one frequency with vac cap and big coil. no store bought garbage. Transmitter on 160 will be one of my 1kw broadcast boxes, 80 will be 1kw or Collins 21E.  Ideal setup would be same ant with relays as needed to match to 160 or 80 with different feed lines and tuner, only common antenna.

KC4MNE


* madmanatwork.jpg.jpg (269.83 KB, 1632x1224 - viewed 382 times.)
Logged
kc4mne
Member

Offline Offline

Posts: 18


« Reply #10 on: December 09, 2019, 10:16:50 PM »

I also have a second 50' tower on the site that is not next to building. all towers are self supporting crank ups, no guy wires.

KC4MNE
Logged
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #11 on: December 10, 2019, 01:41:40 AM »

Thanks for all the ideas
AC0OB, what would the dimensions be for the 80 M version. Also the 70' tower is close to a building so the skirt wires can only be 12" away from the corners of the tower. Tuner not be a problem, will be L fixed on one frequency with vac cap and big coil. no store bought garbage. Transmitter on 160 will be one of my 1kw broadcast boxes, 80 will be 1kw or Collins 21E.  Ideal setup would be same ant with relays as needed to match to 160 or 80 with different feed lines and tuner, only common antenna.

KC4MNE


Okay so I think you're saying a 160 meter folded unipole is out.

As I stated earlier if your tower is well grounded and has a radial field, and for 80m, run a wire from your tuner to a spot on the tower at about a 45 degree angle.

* Shunt fed Monople.pdf (91.22 KB - downloaded 138 times.)
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
kb2vxa
Member

Offline Offline

Posts: 162


I modulate, therefore AM


« Reply #12 on: December 12, 2019, 11:52:57 AM »

I don't know why I seem to be the only KISS believer, the simpler you make a job the less work and expense there is in it. Here's a better picture of the K2PG Pennsylvania tower, 60ft self supporting with the ATU feeding the bottom commoning ring that's about waist high. Self supporting is the way to go if you're really picky about the skirt wires being exactly 120 degrees apart, but the West Creek tower proves neither that nor the guy spacing is THAT critical. Toss out the EE manuals and think like a HAM, go with whatever works. Phil is the EE, I'm the ham, I had to rework his entire ham station and make a few wiring changes to his house to get everything working as he intended. I'm not a miracle worker by any stretch of the imagination, it took about 3 months of experimentation to get all the bugs worked out.

Why make things so complicated and finding out the hard way the devil is in the details? My post back there explained the antenna to a T match, what's in the typical AM station's dog house(s). Why not take that design and run with it? High power Ls and Cs are out there waiting to be scrounged, that's how I made my Frankenstein Laboratories 10KW ATUs. A 160-75M remotely switched ATU for a say, 1885-3885 is about the simplest, RF relays may be had from Surplus Sales of Nebraska. http://www.surplussales.com/Relays/rfopen.html If you scroll to the bottom of the page you'll see one similar to one at the WERA transmitter site mounted on the ceiling to switch the main and standby transmitters and the dummy load. There was one like it at the K2PG West Creek QTH switching between the Collins 20V and 20V2 transmitters. That's an unusual way to get 4 160M AM frequencies, 2 in each transmitter. I couldn't find the RF relay I used in his sequenced T-R relay system, a BMF ceramic insulated wide spaced DPDT relay with both sides paralleled. FYI tube type AM transmitters need to be sequenced for T-R work or finals become popcorn. I don't know why they want so much for that monster relay, but if it can't handle 4KW PEP 100% modulated AM nothing can. For the EEs out there, the ATU needs to match 52 ohms to approximately 400 ohms. Get your slide rules out, no cheating with EZ NEC software.(;->)
Logged

73 de Warren KB2VXA
Station powered by atomic energy, operator powered by natural gas.
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #13 on: December 13, 2019, 03:57:18 AM »

I also have a second 50' tower on the site that is not next to building. all towers are self supporting crank ups, no guy wires.

KC4MNE

For 80 meters a full wavelength is 263 feet or 234 feet when including propagation velocity.

A 50 foot tower then is about a 0.21 wavelength.

Calcs show the Impedance Matching point will be about 24 feet above ground.

The spacing of the 48.5 foot long skirt wires would be 10 inches away from the three faces.

The bottom feed ring will be about 1.5 feet above ground.

Phil - AC0OB

Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
kc4mne
Member

Offline Offline

Posts: 18


« Reply #14 on: December 21, 2019, 02:50:00 PM »

Hi DMOD,
What do you use to model the folded unipole antenna's? EZNEC ? if yes do you have a sample model you could share? my email is KC4MNE@GMAIL.COM

Thanks
Logged
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #15 on: December 21, 2019, 06:14:37 PM »

Hi DMOD,
What do you use to model the folded unipole antenna's? EZNEC ? if yes do you have a sample model you could share? my email is KC4MNE@GMAIL.COM

Thanks


I use a proprietary package I programmed in MatLab from the equations found in
 
https://www.accessengineeringlibrary.com/content/book/9780071474856


Phil
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
kb2vxa
Member

Offline Offline

Posts: 162


I modulate, therefore AM


« Reply #16 on: December 22, 2019, 03:00:56 PM »

I've seen shunt fed towers and I've seen grounded vertical folded unipoles. What I haven't seen is a shunt fed grounded vertical folded unipole... but I'd like to see one if you guys are really serious about it.

Then there is a broadband dream antenna abandoned in Russia...


* Russian Woodpecker Duga-3b.jpg (402.96 KB, 800x640 - viewed 275 times.)
Logged

73 de Warren KB2VXA
Station powered by atomic energy, operator powered by natural gas.
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #17 on: December 22, 2019, 07:18:09 PM »

I've seen shunt fed towers and I've seen grounded vertical folded unipoles. What I haven't seen is a shunt fed grounded vertical folded unipole... but I'd like to see one if you guys are really serious about it.

Then there is a broadband dream antenna abandoned in Russia...

The Folded "Unipole" IS shunt fed. The tower is grounded. The skirts are grounded to the top of the tower and allowed to fall along the Face of the tower to about 1/2 to 1.5 meters above the ground or wherever is convenient. The skirt wires are attached to the tower at a point for a 50 ohm match or close thereto. The skirt is shunt fed at the bottom to a shunt feed ring which serves as both the feed point and to tension the skirt wires.


* Folded Unipole 1.jpg (3.57 KB, 240x180 - viewed 196 times.)

* Folded Unipole II.jpg (51.62 KB, 429x600 - viewed 242 times.)

* Folded Unipole Bottom Loading 4.jpg (8.02 KB, 194x259 - viewed 201 times.)
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #18 on: December 22, 2019, 07:27:33 PM »

More Folded Unipoles.

Phil - AC0OB


* Folded Unipole 3.jpg (4.75 KB, 183x275 - viewed 187 times.)

* Folded Unipole 5 Diagram.jpg (8.39 KB, 170x297 - viewed 228 times.)
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
WD5JKO
Member

Offline Offline

Posts: 1996


WD5JKO


« Reply #19 on: December 22, 2019, 08:45:22 PM »


I built a similar antenna from the May 1979 issue of Ham Radio. Used coax feed, and a tuner at the tower base. Here is a link to the PDF, and then go to page 38:

https://tinyurl.com/t4cubze

This was a very interesting antenna. Would reach out across the country on 75m, and yet was at least 20dB down for short skip when compared to a low dipole. On 160m, one night I broke into a group of W2's in NY, and I was in Texas. Was running 25 watts AM and they heard me! This was in the 1980's before Al Gore invented the internet...man made QRN was a lot lower back then.

Jim
Wd5JKO
Logged
W1ITT
Member

Offline Offline

Posts: 573


« Reply #20 on: December 22, 2019, 10:24:05 PM »

It's rather curious that the Ham Radio Magazine article that Jim linked uses only a few ground rods and touts that it saves thousands of feet of wire for ground radials.   Over in the Middle East, I set up a pair of four square medium wave (AM broadcast) antennas using folded unipoles as pictured as the radiating elements.  But each radiator had a full complement of 120 radials under it.  We were out in the desert but right next to the Gulf of Oman.  Both arrays had complex switchable phasing networks so that one had four directional patterns and the other only three patterns.  It was a lot of fun to set up, but it worked like gangbusters when fed with half a megawatt.  By running the skirt tap point up and down the tower, one can set the base impedance where it's wanted to make the networks happy.  I was able to hear one of them occasionally back here in Maine when I got home.
Anyone who tries one is encouraged to use something better than a few ground rods.
73 de Norm W1ITT
Logged
DMOD
AC0OB - A Place where Thermionic Emitters Rule!
Contributing
Member
*
Offline Offline

Posts: 1768


« Reply #21 on: December 22, 2019, 10:57:25 PM »

Folded Unipoles can improve the E-field of a broadcast station where the ground system has been degraded but who ever got the idea or made the statement that the folded unipole doesn't require a good ground for maximum efficiency is totally incorrect.

The folded unipole needs to work against a good counterpoise as do any vertical antennas.


Phil - AC0OB
Logged

Charlie Eppes: Dad would be so happy if we married a doctor.
Don Eppes: Yeah, well, Dad would be happy if I married someone with a pulse.NUMB3RS   Smiley
w8khk
Member

Offline Offline

Posts: 1200


This ham got his ticket the old fashioned way.


WWW
« Reply #22 on: December 22, 2019, 11:13:38 PM »

snip...... who ever got the idea or made the statement that the folded unipole doesn't require a good ground for maximum efficiency is totally incorrect.


I have found most of what John, WB5IIR (SK) wrote to be reasonably accurate, but I think he slipped up on the ground rod vs. radials issue as written on page 38 of the article in HR for May, 1979, (linked in reply 19 by Jim, WD5JKO).

One of the features Haerle lists for the folded umbrella, aka folded unipole, is "Fully effective without ground radials".
Logged

Rick / W8KHK  ex WB2HKX, WB4GNR
"Both politicians and diapers need to be changed often and for the same reason.”   Ronald Reagan

My smart?phone voicetext screws up homophones, but they are crystal clear from my 75 meter plate-modulated AM transmitter
R. Fry SWL
Member

Offline Offline

Posts: 114

Broadcast Systems Engineer (retired)


WWW
« Reply #23 on: December 24, 2019, 06:37:14 AM »

Would like to add a "folded uipole", maybe "dual band shortened folded unipole" would be a better description to use on 80M and 160M. My tower is 70' tall. However have not found much on measurements online. Any ideas?  I have space for some ground radials, but not a perfect circle of radials around the tower.

Ok, here is the best I can do for now for a 70 ft. tall triangular metallic tower with a 1 ft. face for 1.9 MHz. This was scaled from one of our broadcast towers. ...


Thought I'd start a study of that folded unipole system using NEC4.2 (see the graphic below).  The gain of that system shown for a perfect Earth is only 0.19 dB less than that of a perfect, unloaded, 90° monopole base-driven against a perfect ground plane.

Less than perfect conductivity of the ground plane reduces the gain of both of those configurations.  For an example, if the folded unipole was using a single, 8' ground rod at its base buried in 5 mS/m Earth, then its NEC4.2 far-field gain would drop to -9.1 dBi, and its feedpoint Z would be about 94 +j 278 Ω.

Is this data, so far, ~consistent with what would be expected?

Logged
kb2vxa
Member

Offline Offline

Posts: 162


I modulate, therefore AM


« Reply #24 on: December 25, 2019, 10:25:24 AM »

Now I see where I went wrong, I think somebody a way back said something about feeding it somewhere above the bottom ring, I saw that as shunt feeding a grounded tower. Like a series fed insulated from ground tower that's still a quarter wave with the current node at the bottom and a high vertical takeoff angle, an ordinary 1/4 wave ground plane.

The whole idea behind a grounded vertical folded unipole is twofold, first the tower is shorter saving expensive steel, and it also has a low vertical takeoff angle that provides a longer direct wave (ground wave is different being long range VLF) thus larger primary and secondary contours aka listener area. That's because the 90 degree point aka current node is at the top of the tower instead of the bottom. The beauty of the beast is longer sky wave propagation for great DX on the longer wavelength bands of 160 and 75-80M. I can't speak on 40M because when the band goes long at night it's clobbered by Area 1 SW broadcasters beginning mid afternoon on the right coast, there goes 4M AM, bye bye. Yeah, there are still a few around, just enough to crowd us down to that tiny slice of CW only at the bottom of the band.

Now did I say anything you guys don't already know? (;->)
Logged

73 de Warren KB2VXA
Station powered by atomic energy, operator powered by natural gas.
Pages: [1] 2   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone © 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.079 seconds with 19 queries.