Mounting vertical antennas

[Per von Zweigbergk-3]

I live in an apartment building in a large city, and I have decided
that basically the only realistic option (besides operating with
stealthy wire antennas) is to mount some form of vertical HF antenna --
and I need to pitch the idea to my landlord, who will obviously have a
few concerns. I'm probably happy enough to accept that if I do things
"as they are normally done", bad stuff won't happen -- but it'd be nice
to have some nice pictures, stories and hard specifications rather than
vague ideas to put forward.

It would be really helpful if I could get descriptions of how *you*
have mounted your HF vertical antenna to your roof, and how reliable it
has been with respect to winds et cetera. Even more helpful would be
pictures of the installation in place!

I'm currently leaning towards having some kind of chimney mount, since
I won't be allowed to make any holes in the roof itself, but I'm open
to other suggestions of course! :-) But I still have some unresolved
questions.

How can ensure reasonable reliability. Obviously, the last thing I want
is for the antenna to come loose and come crashing down on some poor
soul or his car. What calculations should I do in order to ensure that
the antenna stays up? And how can I accomplish that if it fails, at
least it should fail in a relativelty safe way. (I.e. not come crashing
down tens of meters. :-)

Also, most guides I've read tell you to mount the antenna to a mast
tube, using U-bolts to secure the antenna itself to the mast. (It seems
that my vertical has holes supplied for just that purpose.) Won't that
decrease reliability -- should I try to mount the antenna directly to
the chimney, or is the mast tubing there for a good reason?

Finally, should I just forget about trying to do this myself, and have
it professionally installed? After all, the stakes with respect to
reliablilty and safety for working at relatively high altitudes are a
bit higher than erecting a horizontal dipole in a couple of trees
(which I have done at my summer QTH I might add. :-) What kind of
people can I expect to have to contact about this, and if I decide to
go professional, how much would it cost reasonably?

--
73 de SM0YUF
Rig: Elecraft K2 -- Serial number 4291 (base model -- almost, but not
quite finished.)

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[Ingo Meyer DK3RED]

Hello Per,

> I live in an apartment building in a large city, and I have decided that
> basically the only realistic option (besides operating with stealthy
> wire antennas) is to mount some form of vertical HF antenna ...

I had the same situation in my apartment. So I solved the problem with a
telescopic mast, which I can errect in a few minutes. The mast is attach with
small part from the building store on the railing of my balcony. No need to
drill a hole in any parts of the balcony and secure to attach. For more
informations please go to www.dk3red.homepage.t-online.de/en/s6.htm#ant1 on my
homepage.
--
72/73 de Ingo, DK3RED   Don't forget: the fun is the power!

    [hidden email]   http://www.dk3red.homepage.t-online.de
      DL-QRP-AG   #824   http://www.dl-qrp-ag.de
       QRP ARCI #11295   http://www.qrparci.org

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[G3VVT]

I would approach it in the same way as mounting a large TV antenna on a  
chimney stack, though the method used may vary from country to country how to  
achieve this.
 
In the UK, traditionally we use a galvanised stranded steel band (lashing  
wire) that passes around the chimney stack which is attached to an antenna  
mounting bracket with "J" bolts to terminate the band and adjust for  tension.
Galvanised steel or aluminium corner plates are placed under the wire  band at
the other three corners of the chimney stack to spread the load on the  corner.
A mast of the necessary length and diameter to mount the antenna is  attached
to the mounted chimney bracket with two "U" bolts. With a vertical HF  antenna
a heavy duty chimney bracket is called for, or two separate brackets  with
separate chimney bands as we used in the early days of TV with large TV  antenna
installations. The galvanised fitting are fairly robust though they  can be
replaced with stainless steel stranded wire and "J" bolts if local  corrosion
was to be a problem. I use galvanised fittings and paint all potential  areas
of corrosion with an automobile body underseal/internal panel rust  inhibitor.
In the UK this is product marketed by Finnegan (Hunting Lubricants)  called
WAXOYL. This product excludes moisture and dries with a surface skin  which also
discourages the gathering of moisture. Our Volvo station wagon  manufactured
in Sweden uses a similar brown coloured product inside it's  automobile door
panels. Antenna fittings painted in this way are still  removable 20 years
later whilst a normal fitting would be rusted solid after  only a few years in
some locations. The moral is if it could rust paint it  which I also do with any
fittings on the antenna itself that could  rust living in a rather wet part of
the UK.
 
In the late 1960's I had an antenna similar to the HyGain 12AVQ  mounted with
two "U" bolts on a 1 1/2" (38mm) stub mast in this way with radials  attached
to the ground connection on the base of the antenna. If a longer mast  is
used the radials could be arranged as guy wires for added strength of the  
installation. The methods used depend on the exposure to wind and the elements  at
the chosen location. The same method I now use with a moderate  sized VHF/UHF
collinear antenna that occupies the prime position on one of  my chimney
stacks. If an external TV antenna were to used and space was  restricted it would be
possible to mount a TV antenna under the HF antenna on  the mounting mast. In
my case I do not have this problem living in an old  house with three
chimneys stacks to cope with the old situation pre central  heating of a fire place
in every room.
 
Served my early work experience in the late 1950's in the Radio  and TV trade
standing on roofs/chimney stacks to install TV antennas.
 
Bob, G3VVT
K2 #4168
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[g4ilo-2]

Another option if you're really stuck: The MFJ Magnetic Loop is a
surprisingly efficient antenna on 20m thru 10m. You could stand it on a
pole on your balcony, if it came to that.

73,
--
Julian, G4ILO. (RSGB, ARRL, G-QRP, K2 #392)
G4ILO's Shack: http://www.qsl.net/g4ilo

Per von Zweigbergk <[hidden email]> wrote:

I live in an apartment building in a large city, and I have decided that
basically the only realistic option (besides operating with stealthy wire
antennas) is to mount some form of vertical HF antenna --  



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[criswat]

A faulty tv aerial installation could also cause a bad TV reception. I think you should a aerial installer for aerial installation...