[Boatanchors] Need suggestions and question on antenna for DX-100

[Rodger]

Hi Bob,

You can use the longwire but I would definitely get an antenna tuner to use
with it; the DX-100 was designed to match a very wide range of impedances
but it turned out in doing so it often led to burnt components in the output
network.  Heathkit restricted the matching range on the B version and had
upgrade kits available for the original to provide the same restricted range
output network.  As long as you use an antenna tuner capable of handling the
DX-100 output you should be okay.  Keep in mind that high level AM puts much
more stress on antenna tuners than SSB or CW so the lower power MFJ and
similar tuners are not advisable.  Operating AM, the DX-100 will produce
around 125 watts continuous carrier output which increases to 500 watts on
modulation peaks.  Thus the tuner gets a continuous heating workout from the
carrier and gets "tested" for flashover on modulation peaks.

I have been using a full wave horizontal loop on 75 meter AM for several
years and I use it as a top loaded vertical on 160.  This antenna is simple
to construct (~275 feet of wire in a roughly square configuration fed with
either coax or balanced feedline and mount it 25-50 feet above ground, mine
is around 35 feet high) and can be fed on 160 by tying the center and outer
conductors together and feeding as a T or vertical.  It will also work on
40-10 with a tuner and it is a fairly low noise antenna.

I use a homebrew L network tuner and this antenna is used with a number of
my vintage rigs including a Johnson Desk KW, Heath DX-100 and TX-1, Drake 7
line, etc.  It seems to work very well on 160 and 80 and I have used it on
the higher bands.

Good luck on getting on HF AM soon!

73, Rodger WQ9E

> -----Original Message-----
> From: boatanchors-bounces at mailman.qth.net [mailto:boatanchors-
> bounces at mailman.qth.net] On Behalf Of Bob Young
> Sent: Sunday, February 18, 2007 1:08 PM
> To: heathkit at mailman.qth.net; boatanchors at mailman.qth.net
> Subject: [Boatanchors] Need suggestions and question on antenna for DX-100
> 
> I'm a new ham, will get my upgrade to general after the 23rd. My question
> is, can I use a 400' LW for a transmitting antenna with a DX-100? It's fed
> with RG-58. Should I get an antenna tuner and SWR meter for this if it is
> OK
> to use? If so any suggestions? This would be temporary until I get a
> dipole
> or something like that. I would like to be able to transmit AM on 160 and
> 80
> meters among other bands. I have the room for a full length 1/2 wave 160
> meter dipole in my back yard but it is not the easiest thing in the world
> to
> do. I wouldn't be able to get it up much over about 30' either.
> 
> thanks,
> 
> Bob Young
> KB1OKL
> 
> 
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