[Antennas] AM Broadcast RX Antenna?

[Hue Miller]

1000 miles out, year round, daytime too? That is a stretch.
You already know, of course, that there's not much of a "match" possible 
to the car radio's AM
antenna. The input to the car radio is for a low capacitance (short in 
terms of wavelength ) antenna.
It's interesting i think that you got substantially better results with 
the CB type whip length.
When i was working, i drove the hills on the Oregon coastal range. In DX 
season i could listen from
Newport, Oregon, to CBC Vancouver 690, KIRO Seattle 710, KFBK in 
Sacramento ( i think ), and a
all-comedy station on 1160 ( IIRC ) from Alberta. The 690 Vancouver 
would sometimes be fighting
it out with XETRA on 690 from Mexico, and a few times Vancouver was 
nowhere to be heard and i
had good copy on the Mexican. This is with a stock radio in a Ford 
Ranger truck.
When i told the service order writer at the dealer that i wanted the AM 
radio noise situation in my
Dodge Caravan taken care of, he told me i needed to go to an auto 
electrics specialty place and
besides, no one uses AM any more, just a few old folks. The noise in my 
van, i think from the fuel
pump, is so bad i cannot DX with it, just the local stations. The 
service people must hate working on
the fuel pump because they all told me just to wait til it fails, not to 
be preemptive about it.

One thing i've wondered about, is in the old Whitney car parts catalog 
was a "car antenna booster"
which was simply some kind of coil that inserted at the base of the 
antenna. However just mentioning
this makes me wonder how you'd install it. The claim was that it would 
pull in more & better. Seeing
as the car radio expects only a certain capacitance hi-Z input, i don't 
see how a coil in the antenna
would help. There's no magic to a coil. Maybe the benefit was 
'psychological'.
-Hue Miller


------ Original Message ------
From: "KD7JYK DM09" <kd7jyk at earthlink.net>
To: antennas at mailman.qth.net
Sent: 11/13/2015 3:54:32 PM
Subject: Re: [Antennas] AM Broadcast RX Antenna?

>The station my wife wants to hear is about 1,000 miles out.
>
>We did notice an improvement when holding the 102" whip against the 
>factory
>antenna, greater signal strength and better signal to noise ratio, I 
>thought
>we could do even better if it was matched to the primary frequency she
>listens to during her morning and evening commute.  She doesn't listen 
>to
>local FM at all, so it's either 660 AM or the satellite radio.
>
>I have a close-body CB mount to modify to match the contour of the 
>truck bed
>and some 1/4" aluminum to make a secondary mount about a foot above 
>that to
>really stabilize things.  On the back side, inside the fender, I can 
>add a
>matching network, then either T into the existing co-ax or remove the
>factory antenna entirely and use just the 102" whip.  We're in a fringe 
>area
>so the longer antenna would no doubt help with reception in general, 
>but the
>primary concern is the DX AM station.
>
>Kurt
>
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