randome wire or MP-1 antenna with FT-980
 

I am really new to ham radio and have a couple of questions. I bought
a used
Yaesu FT-980 and now am trying to set up an antenna for it.

Option 1: AT-100 Pro / 4:1 balun / randome long wire. I am
experimenting with this in my office at the moment. I cut a copper
wire (about 3/16 inch strand) and attached it to the antenna line of
balun. I ran another short wire to the ground of the wall receptacle.
Connected balun to AT-100 Pro with 25 foot coax, then connected the
antenna tuner to FT-980. I powered up the transceiver and tried a few
differant frequencies. The AT-100 Pro made some grinding noise and was
able to bring the SWR down to around 2, the power meter went to about
100. The antenna was drapped across some cubicles (dilbert office).
After a short while the antenna wire got a bit hot to touch, and
tingled a bit when I touched it. Is this normal? Should I use a longer
wire?

Option 2: I am thinking of getting an MP-1 vertical antenna instead of
random wire. Can I use the antenna tuner with this? Will it heat up?
How do I ground it? Do the counterpose wires spread out act as a
ground?

Sorry for all the questions, I am a total beginner.

Thanks for your help,

Glenn
PAMREMOVE

Glenn wrote:
I am really new to ham radio and have a couple of questions.ffice).
After a short while the antenna wire got a bit hot to touch, and
tingled a bit when I touched it. Is this normal?
Yes - it's not a good idea to touch an antenna when it's transmitting -
especially 100 watts.

Option 2: I am thinking of getting an MP-1 vertical antenna instead of
random wire. Can I use the antenna tuner with this?
Yes - although you may not need it: the MP1 has an adjustable coil that
should do the matching for you, rendering the tuner superflous.

Will it heat up?
Shouldn't if it's tuned up right.
How do I ground it? Do the counterpose wires spread out act as a
ground?
Yes.

Hi, Glenn -

I hope the experts will have something to say, but someone ought to
mention that you shouldn't expose your officemates to 100W of rf energy.
Can you get that random wire outside?

Those cubicle dividers have metal tops & skeletons, no? Those are no
doubt coupling to the antenna wire if it's draped over them. This just
generally messes up the situation. Another reason to get that wire outside.

The wire heating up is no doubt due to this coupling with office
furnishings. The voltage varies along the wire, and at places it can be
thousands of volts. A metal object in contact with such a spot could arc
with the antenna wire.

An antenna wire should be as high as possible and *in the
clear* (not touching any buildings, tree limbs, lamp posts, etc). That's
why an insulator is put at the end of an antenna wire, with a rope going
the rest of the way to the antenna support (tree, etc.)

The MP1 has been used and it works. Being a shortened vertical, it tends
to radiate mostly upwards on the lower bands. This can be good (40M in
the daytime to talk within a few hundred miles) or bad (40M at night
when you might want to do dx may not be so great). Can you put the MP1
outside, even temporarily? The counterpoise wires constitute the rf
"ground" in that case. They should be cut to 1/4 wave on the lowest band
you want to operate on and fanned out around the base of the antenna.

Please don't hesitate to ask more questions. Hope this helps.

Antenna boys - please chime in!

73 - Lee H, NB7F