Pages: [1]   Go Down

Author Topic: E Factor 2 Meter & 440 Antenna - Attic Install?  (Read 375 times)

KK7AAG

  • Posts: 2
    • HomeURL
E Factor 2 Meter & 440 Antenna - Attic Install?
« on: August 25, 2021, 01:56:40 PM »

Hi,

Is anyone using the E-Factor antenna using an attic mount? I just passed my technician exam, and sitting for general next week. Right now, due to the common HOA headaches, I am looking for both a dual band 2 meter, and an HF antenna that I can install in my attic. I want to resolve the antenna issue first before I invest in radios, and the rest of the gear. So I am in "research mode" at this time.

I got one of the TRAM bases where you can attach a mobile. Basically this gives you the radials, but the only thing I can reach is one local repeater, haven't been able to do Simplex on the 146520. Prior to taking my tech exam I purchased a Baofeng as a listening device just to see what type of local traffic there was here in Heber City UT, and there is traffic, but the radio is not the best, even though it is the 8 watt version.

I would love to hear from some of you who have successfully resolved the antenna issues. Unfortunately a dipole will not do the job, I simply do not have enough space to hang it. I want to have access to 6 meter through 40 meter. Realistically the 80 & 160 bands are not going to be possible, unless there is an antenna out there that will allow me to access those bands, and it would have to be attic installed.

I am looking at the MFJ Mag Loop, and the E-Factor for VHF/UHF, but haven't been able to find too much on these with regards to attic installs. Thanks for reading, all feedback very much appreciated!

73's
Louis
KK7AAG
Logged

K4FMH

  • Member
  • Posts: 681
Re: E Factor 2 Meter & 440 Antenna - Attic Install?
« Reply #1 on: August 25, 2021, 02:26:08 PM »

Congratulations Louis! You are doing the right thing by researching the possibilities before buying equipments. Many do not have this level of patience.

Here are my experiences from building a house in an HOA neighbor without trees, although in 10 years a couple have grown to 20+ feet or so.

I installed dual-band Ventenna over one of the exhaust pipes from a bathroom. The pigtail is in the attic side of the roof. Now, I’m on a bit of a bluff in my location and the Ventenna is about 25’ above ground. I get all of my area repeaters on both bands with a high level of quieting. Highly recommended!

I also have one of the Diamond X50a ground planes inside my attic and behind a foil-backed radiator barrier. I get very good but not quite as far from the same radio as the Ventenna. It would work too if I didn’t have the Ventenna.

Go into your attic with your HT and see what repeaters you can reach and note them on paper. You only mentioned one with the Tram antenna setup. Thus will be a good baseline. Go outside and see what you can reach. Make a comparison column. It may be the lack of TX power if you can hear them but not get into them.

Take a look at Repeaterbook.com and map your area repeaters, noting the distance to your location. Compare that to the results above. They may tell yiu about the likely coverage you may get with a proper ground plane, J-Pole etc. with 50 watts in a transceiver.

Good luck and enjoy the process!

73,

Frank
K4FMH
Logged

K0UA

  • Member
  • Posts: 9589
Re: E Factor 2 Meter & 440 Antenna - Attic Install?
« Reply #2 on: August 25, 2021, 02:52:16 PM »

I made a simple 2 meter J pole in the attic many years ago, and it will hit a lot of repeaters, even some at 50 miles away (the high ones). It is home made out of 1/2 inch electrical conduit and its fittings. Not even copper, it is steel (not a great idea) but it does work. It is my bad weather antenna.  Now don't get me wrong it is not near as good as my old Hustler G6 up about 50 foot on top of the tower, but hey it does the job I need it to do, and it cost next to nothing. My point is attic antennas, especially on VHF/UHF can work fairly well. Not as good as outdoor antennas at even the same height, but often it is "good enough" Up there is also a 40 thru 10 fan dipole made from small gauge wire stapled onto the rafters. I haven't used it in years, but I used to make contacts on it before I got proper outdoor antennas. If it is all you got, its all you got.
Logged
73  James K0UA

WB6BYU

  • Member
  • Posts: 20896
    • Practical Antennas
Re: E Factor 2 Meter & 440 Antenna - Attic Install?
« Reply #3 on: August 25, 2021, 03:22:29 PM »

Quote from: KK7AAG

Is anyone using the E-Factor antenna using an attic mount? ...



First of all, the E-Factor antenna (from what I can see on their
web site) is horizontally polarized.  If you want to work repeaters,
you need a vertically polarized antenna.

So, regardless of how well it might work in an attic, it probably
isn't what you are looking for.


How tall is your attic?  Unless it is close to 8' or more high at
the peak, you probably can't do any better for an omnidirectional
2m antenna than a vertical dipole or equivalent (J-pole, ground
plane, etc.) suspended as high as you can get it in the center of
the attic.  (Performance does depend on the roofing material,
of course.)

I'm currently using a half wave coaxial dipole in my attic, and I
have no problems with the local repeaters, as well as some
more distant ones.  I didn't have access to the attic in that part
of the house, so I drilled a hole in the ceiling in a closet and stuck
the antenna up through the hole.  You have to open the closet
door, step inside, turn around, and look up above the door jam to
see that there is an antenna there (other than the coax snaking
out through the door, of course).

If you have a limited number of repeaters that serve the valley,
and signals aren't good enough using such a vertical, then I've
built simple beams (yagis or quads) and mounted them in the
attic.  #12 wire for the elements and wood or PVC pipe for the
boom is quite adequate, since they are protected from the
weather.  For a limited number of directions, you can build
several and align them for best signal (which might not always
be the direction measured on a map), then choose among
them with a switch, which is often simpler than trying to
arrange a rotator on an antenna.

At one point I had a pair of 5-element beams pointed at a distant
repeater that I wanted to use.  They would have worked better if
they weren't pointing out through the end-wall of the attic, as it
was covered in stucco, which contains a metal screen like chicken
wire mesh.

Getting the antenna outside, even if you have to build a dummy
roof vent to disguise it, will usually work better.



Quote

...I got one of the TRAM bases where you can attach a mobile. Basically this gives you the radials, but the only thing I can reach is one local repeater, haven't been able to do Simplex on the 146520...



Heber City isn't the ideal location for working lots of repeaters
on 2m.  It is surrounded in most directions by ridges that are
2000' or more above the valley floor.  The only repeaters you
likely will be able to work will be something in town (or possibly
North up towards Hideout, depending how far East you are),
or those on high peaks in the surrounding area. 

The same goes for contacting stations on simplex:  your terrain
puts you at a disadvantage for working any significant distance
with an attic antenna.  That doesn't mean it is impossible, but
it may require a beam antenna and higher power.


So the first step is to talk to any local hams about what repeaters
you should expect to be able to hit, then make sure that you have
the right access tones and offset programmed into your radio.



Quote

Prior to taking my tech exam I purchased a Baofeng as a listening device just to see what type of local traffic there was here in Heber City UT, and there is traffic, but the radio is not the best, even though it is the 8 watt version.



Power output isn't the best measure of a hand-held radio.  Even
the 5 watt models may get too hot to hold comfortably after a
few minutes at full power.

Perhaps of more concern is the susceptibility to overload when
a radio is connected to an external antenna, when signals
throughout the RF spectrum can overwhelm a radio that is designed
for use with a short, inefficient antenna.

While the HT is convenient for use while walking around, a mobile
rig with 25 - 50 watts or so likely will make it much easier to hit
the available repeaters.  My personal approach is not to plan on
running a radio at full power for my usual operating:  I'd generally
try to improve my antenna until I use 10 watts or so for my normal
operation, and use the highest power setting only when necessary.



Quote

I would love to hear from some of you who have successfully resolved the antenna issues. Unfortunately a dipole will not do the job, I simply do not have enough space to hang it. I want to have access to 6 meter through 40 meter. Realistically the 80 & 160 bands are not going to be possible, unless there is an antenna out there that will allow me to access those bands, and it would have to be attic installed.



That also depends on how large your attic is.  40m and 80m
can be great for local contacts using NVIS (basically radiating
straight up, so the mountains won't block it).  It is fairly easy
to make a half-sized antenna work pretty well - we recently built
a 40m + 10m dipole for a neighbor ham to put in his attic that
was about the same length as a 20m dipole, giving 3-band
operation in a relatively short space. 

In some cases, you might do best with as long of a doublet as
you can fit in the attic, generally with the feedpoint at the top
center and the wires stretched out to opposite corners, then
bent around the side walls for some extra length, then put a
remote autotuner at the feedpoint.  That certainly saves a lot
of time climbing up and down to the attic to adjust the various
wires to resonance.

Another options is to run a loop of wire around the eaves of the
roof, often behind the fascia board where it is virtually invisible.
That can be fed with 300 ohm twinlead (or just two "sorta-
parallel" wires) to a tuner for multi-band operation.  Depending
on the length, it might work better on 80m as a bent dipole
rather than a continuous loop.

At the moment I have a 40m doublet on my roof, using thin wire
with mottled insulation, and thin black cord to tie off the ends.
The feedpoint is hanging from the chimney, and the whole antenna
is virtually invisible from the street - at least until the sun glints
on the wire, or we have frost or an ice storm.  With wood shake
roof I've just tucked the wire under the corners of the shingles,
but asphalt shingles are more lossy and affect the resonant
frequency quite a bit unless the wire is more elevated.

K0UA

  • Member
  • Posts: 9589
Re: E Factor 2 Meter & 440 Antenna - Attic Install?
« Reply #4 on: August 26, 2021, 09:49:39 AM »

And speaking of that crawling back up into the attic to get that multiband fan dipole tuned, let me tell you it was quite an grueling thing to do in the heat of summer. I must have made dozens of trips back and forth to get all of the "legs" trimmed out to the lowest SWR. There always seems to be some interaction on the bands. But I got it done. At that time it was all I had for an antenna for HF.  I haven't used it in years since I got my outside antennas put up.
Logged
73  James K0UA

KF6HHH

  • Member
  • Posts: 50
    • HomeURL
Re: E Factor 2 Meter & 440 Antenna - Attic Install?
« Reply #5 on: September 18, 2021, 04:06:00 PM »

I have a Maldol HVU8 mounted in my attic.  Not the greatest antenna in the world, but the “HVU” stands for HF, VHA, & UHF, so it’s an all-in-one antena.  Something to look at.  As an FYI, I don’t use it for 2M/440 as I had a Diamond X50 that works great from the attic.
Logged

KK7AAG

  • Posts: 2
    • HomeURL
Re: E Factor 2 Meter & 440 Antenna - Attic Install?
« Reply #6 on: September 21, 2021, 06:02:26 PM »

KF6HHH,

Hey thanks for the recommendation. I ended up going with the Ed Fong DB1 J-Pole and a Yaesu 2980 VHF 2 meter single band radio. Working great! That radio is a tank, very well made, excellent performance. The Ed Fong antenna also works excellent.

I ended up getting a single band 2 meter radio because other than repeater traffic, there is zero absolutely zero traffic on the simplex 520, and both the 220 & 440 bands. So given the lack of local traffic and line of sight performance associated with the 3 bands, I opted to just get a 2 meter radio. Didn't see the point of getting a triband if none of the bands are used locally.

Louis
KK7AAG
Logged
Pages: [1]   Go Up