From WT Jones, WN3LIF: Last week I sent a request out to the EPA ARES group. The question, posed by WB3BNY, EC for Snyder/Northumberland Counties, was what works best for High Frequency Contact with PEMA in Harrisburg.
I have to say that we have gotten some good feedback and I promised to share what I got with everyone. Given the fact that we have a wide geography to deal with I don’t think it will be a one size fits all solution. And some of you have what you have and will have to live with that until they remodel the building again. But here are the concepts that I received and in no particular order…
Wayne County – Hank Grilk, WA2CCN:
At the present time the Wayne County EOC does not have any active HF capability. The County owns a NEW Kenwood HF transceiver, but not HF antennae have been installed.
At my home station I use a 2-element half-log-cell antenna on 75/80 meters. It’s mounted in an inverted configuration with the apex at approximately 57’, and the ends up about 20’. This antenna has a double-dip SWR with a worst-case SWR of 1.8:1 across the entire 3.5 – 4.0 MHz band. I believe this is the same antenna that’s used at the Luzerne Co. EOC. It works GREAT… just ask any EPA station that has checked into the EPAEPTN what kind of signal WA2CCN puts out 😊.
Attached is a short article on this antenna that I’ve prepared. Note that I only use this antenna on 75/80M – – – on 40M I have a 40M Rotatable Dipole up about 65’, and on 10-12-15-17-20M I use a 8-element Tennadyne Log Periodic antenna.
It is [possible to add a 40M version of the 2-element half-log-cell antenna INSIDE the 75-80M 2EHLC !!! I’ve modeled it in EZ-NEC Pro.
Anyway, have fun.
73, Hank – WA2CCN
From Bob Brown, KA3IPZ, EC for Lycoming County:
1. Type of Antenna: Lycoming ACS has 2 multi-band folded dipoles. One is a B&W (Barker & Williamson) – oriented E-W. One is an Icom AH-710 – oriented N-S
2. Physical Dimensions: Icom AH-710 wire antenna length 80.3’ non-resonant. B&W -length is similar to the AH-710 above
3. Feed type: (coax/open wire/what ever), both are coax fed
4. Height: Both are mounted on the roof of the County EOC (2 story brick building). The B&W is mounted approximately 10’ above the flat roof. The AH-710 is mounted about 5’ above a pitch roof
5 Structure that the antenna is mounted on: The B&W is mounted above a flat roof (rubber / gravel). The center point is mounted to a wooden support pole that is along the edge of the roof. The ends are tied off to metal poles also mounted along the edge of the roof. The Icom AH-710 is mounted above a pitch roof. The center point is attached to a support rope running from a cupola in the center of the ridgeline to a metal support post along the edge. The ends are tied off to support poles at the N & S ends of the roof.
6. Your own estimate of success with communicating with PEMA Harrisburg: We normally are able to check into the Central and Eastern PA ACS Voice nets (80-90%). There have been occasions when we had to be relayed, but the majority of the time, we are able to get in. We normally use the B&W folded dipole (Oriented E-W) for voice nets. We have had success checking on to the PaNBEMS Sunday AM nets using the Icom AH-710 folded dipole (oriented N-S).Currently we are in the top 5 for checkins for 2019. As WT Knows, we have occasionally had to rely on relays on occasion as most PaNBEMS net controls are in the Philly area. We have trouble getting into NjNBEMS without a relay.
From Don, K3DCS, EC for Adams County:
To support two HF operating positions Adams County has two HF antennas on the roof of the EMA building. Both work well into PEMA SEOC in Harrisburg.
#1: -80M horizontal wire loop – tunes all bands 10M to 80M using auto tuner
-Total length about 260’, in a rectangle configuration
-Coax feed to balun using RG213 with Polyphaser lightning protection
-Approximate height to top of each post to ground is approximately 35’
-Mounted around the four corners of the roof over the apparatus bay of EMA building. At the roof four corners are mounted 10’ metal posts, antenna mounted at the top of each
#2 – Radio Works Carolina Windom 80 Special (I believe this antenna may no longer be available)
-Total length including both horizontal elements is 133’, vertical element is 22’ long. Hung in a slight inverted V configuration.
-Coax feed using LMR400 with Polyphaser lightning protection
-Approximate height ground to top of post is 40’.
-Post is mounted in the center of main EMA building roof. The center of the antenna is mounted to the top of the roof post with ends of the two horizontal elements tied to lower post structures on the roof.
For Carolina Windom see attached photo. Just in from the left side of the photo you’ll see a reddish color post with a gray mast attached to the top of it. That is the antenna center. Then you see running to the right a thin white rope. This supports the one element of the windom. The other element isn’t visible in the photo. (The four long white antennas are dual band VHF/UHF and support the four VHF/UHF operating positions.)
We also have a third HF radio position that, if needed, we can connect to a third external HF antenna using an existing exterior coax stub. That antenna can either be our portable multiband vertical HF antenna or a second 80M horizontal loop installed above the parking lot using existing 30’ tall light poles. When needed it takes about 30 to 45 min to set up the parking lot loop. We frequently use all three HF antennas during field day (3F class), the parking lot loop works as well as the loop over the apparatus bay.
I should point out that the EMA building is at a great location for HF/VHF/UHF operation. The building is almost four miles east of Gettysburg in a rural area so radio noise is generally low plus the building sits on a hill allowing good performance for any type antenna. Looking in the distance of the attached photo, which is facing west, are mountains about fifteen miles away, The mountain are mostly Michaux State Forest.
Then of course propagation is the largest influencer for any HF communication so best to also check those conditions at the time of testing antenna configurations and take that information into consideration before making a final determination on an antenna config.
Hope this helps.
Don
Don Schmitt K3DCS, Auxiliary Communications Officer
Adams Co Dept of Emergency Services
ARRL ARES Emergency Coordinator Adams County, PA
From Harry, N3FMO, EC for Lancaster County:
The Lancaster County EOC also has an off center fed dipole. Coverage is not what I consider great. They were unable to contact PEMA during one of the exercises. It is mounted on top of the EOC but I am not sure how far above the roof. It is fed with coax.
At home I use an Alpha-Delta dual sloper for 160/80/40, with the center at 35 feet and the ends at about 8 feet. (hardly ever use it on 160 ) It is fed with RG8 type cable. A sloper really doesn’t work well unless it is mounted under some type of HF beam. The beam is sort of a capacitive hat.
I have had no difficulty contacting PEMA on 80 and 40 with 100 watts, but then I am only about 20 miles away.
– Harry, N3FMOLancaster County EC
From our Section Manager, George, W3GWM:
I know you are only looking for DEC’s and EC’s. I’m using a G5RV on a 65 foot mast. Reliable communication to PEMA Harrisburg. The antenna is 135 feet long. Feedline is ladder line from 4:1 Balun, coax to Balun.
100% success to Harrisburg. I hear all counties and participating EOC’s on the Sunday Morning Central Area ACS Net when I’m NCS. I hear all counties on Eastern Area RACES Net.
73,
George W3GWM, Eastern PA Section Manager
From Dave, KB3YCK, EC for Chester County:
From Don, WA1ELA, EC for Berks County:Berks County HF is not functioning because of an antenna problem. We can’t get our 40/80 meter to resonate because it is mounted 8 feet above a metal roof.
73,Don B WA1ELAThat metal roof is a problem.
Chester County Details:
1. Buckmaster OCF 7 band (DX-OCF-HP) antenna rated for 3kw
2. 90 foot leg, and a 45 ft leg, 135ft total3. Coax feed line4. About 15 ft above the roof of the Chester County Government Services Building Puts it at about 65 ft AGL.5. ,anchored on one end by to a 20ft roof mounted antenna tower, and the other end to the main antenna tower for the County.6. Very comfortable with ability to reach PEMA — the antenna tuned up just fine with the internal tuner on our Kenwood 590SG, and was used quite a bit during Field Day on. several different bands.
73,
David Flad / KB3YCKCCAR ECDave notes that the part number is from Ham Radio Outlet (www.hamradio.com)
From Pete, VE3HOH, AEC for Schuylkill County:
As the Schuylkill Co. EOC is on the side of a hill, we used the wire fence posts of the parking lot just above the building to mount some empty PD220 station master antenna fiberglass shells. We used 3, and strung along the tops of them are the best part of a 75m full wave wire loop. One end (or corner) is at the short tower on the EOC rooftop, and the SE corner is attached with some nylon rope to pull it that way. It’s a bit slanted, but we seem to be getting great reports.
We also had a G5RV or some kind of trap dipole, but the traps were shot due to aging and weathering, It’s only a 40 meter dipole, also a bit slanted. We have 2 Comet GP6 verticals on the short tower, one on top, the other offset to the side a bit. That replaced a rather unwieldy Cushcraft 11 m Yagi, which was rather useless. we plan to have some 6m and 220 up there as well. Also planning some remote HF operation from the Burma Rd. or Park Place site using crossband RF links for some security. Some fixed Yagis may be required to do this.
We have had some outstanding signal reports using the 75m full wave loop. It was the best 75m antenna I have ever used. It was originally in my backyard. It amazes me every time. I think the NVIS is pretty good on it. It is also the least noisy of any HF antenna I have ever used. I won’t use a vertical. They are a waste of time. Never worked well on Field day, and RX had way too much noise.
Hope this helps.
73 Pete ve3hoh/w3
So there is a wide range of solutions. Two of the solutions are loop antennas. Don, K3DCS, and Pete, VE3HOH, both use them and report good results. Loops can be directive based on the feedpoint but they are good radiators. 260ft means about 65ft on a side.
There are other things that might be tried. A reflector/counterpoise/whatever 1/4 wavelength piece of wire under the elements of the dipole at Synder/Northumberland to act as a reflector for the NVIS situation. NVIS and on a building can be a problem. Something has to reflect the signal up and the roof of the building and roof may absorb it instead of reflect it.
In Luzerne County there is an 80/40 meter trapped dipole at 60ft+. Works well into France on 40m. The jury is still out since it has not been tested with Harrisburg as yet.
That might be something that we should ask our ACS friend, W3TMB, to arrange. A day of testing with Harrisburg’s KB3NIA. That might prove to be useful.
So there you have what I have gotten.
I might as well add my $.02 here. My dipole’s center is about 25ft up. Runs over a chainlink fence which I think makes it perform. It is not in a straight line which again I think helps to be directional over the state. It acts like a corner reflector pointing toward the Southwest. So KB3NIA has been able to hear me and I can hear him. I have a new end fed wire that is still waiting to be wrung out. My friend, K3NDB, created a 9:1 balun for it so I owe him some reports.
And a loop really looks like it will fit here. More wire in the air.
But this is a gamble. In any case, keep the high current part of the antenna as high as you can. Try to orient the lobes toward Harrisburg. Put as much wire in the air as possible.
That is the best I can tell anyone.
Have a good week and if you have move info to share reply to this email and I’ll see that it gets out.
—
73,
WT Jones
WN3LIF
ARRL Amateur Radio Emergency Service
wn3lif@w3luz.org <—
Eastern PA District 3 District Emergency Coordinator
Eastern PA District 2 Acting District Emergency Coordinator
Eastern PA Assistant Section Emergency Coordinator
http://www.w3luz.org