Date: Tue, 13 Dec 2011 08:52:15 -0700
Reply-To: OlRivrRat <OlRivrRat@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: OlRivrRat <OlRivrRat@COMCAST.NET>
Subject: Re: Integrated AM/FM and Stealth CB (alarm) Antenna -- Anybody?
In-Reply-To: <4ee7401c.68b8ec0a.35ec.0211@mx.google.com>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Hey Derek
I know next to nothing about CB but your post here peaked my
curiosity & while
doing some browsing on the WWW regarding the subject I stumbled onto
this site that
appears to maybe have something that might be a solution for you.
http://www.eglidegoodies.com/id126.html
You mention " inside the fiberglass " so I'm assuming you have a
Westy & so I was
looking around to see if there might possibly be an antenna that could
be hidden in the
luggage tray. If CB antennas don't need to be vertical & exposed it
seems that there may
be all sorts of solutions available.
ORR ~ DeanB
On 13 Dec , 2011, at 5:07 AM, Derek Drew wrote:
> This email is a query for someone knowledgeable about radio and CB
> antennas to speak up.
>
> I've been parking for 30 years on the streets of Manhattan, and have
> had little trouble. But its still nice to have the assurance of the
> beepers going off if the bad guys come. In general, if they see
> anything inside the van, they break in, but if they don't see
> anything they don't, possibly because the van is too weird looking
> and the owner's reaction to its being entered too unpredictable for
> comfort. By contrast, I used to find people sleeping in my 72 bus all
> the time in NYC in wintertime, but they never hurt anything aside
> from the lingering after-smell of that type of person.
>
> I have a car alarm that transmits on a CB frequency (27Mhz) to alert
> my beepers if somebody enters the vehicle while I am away from it.
>
> When I have to park too far from the apartment or be very high in a
> tall office building, I turn a switch that ups the power of the 27Mhz
> alarm signal from 4 watts to 50 watts, and this allows me to depend
> on the signal penetrating basements and reach 6 long city blocks
> instead of 2.
>
> I am having to mess with my antenna now and am wondering if anybody
> had worked out how to get a quality setup for the antenna to transmit
> on the CB bands as well as general AM/FM use. I could install a
> dedicated CB antenna, but I'd prefer to use the factory OEM AM/FM
> antenna for this purpose, or if I install a 2nd dedicated CB antenna
> instead, I'd like it to be stealthy and not hurtful to the eye. (Most
> CB antennas hurt my eye, or hurt themselves whacking trees above
> while driving on parkways.)
>
> Normally, trying to use the stock antenna for both CB and AM/FM use
> is possible, but the CB functionality is greatly degraded because
> such antennas are the wrong length, and AM/FM antennas are generally
> a joke for CB use for many other reasons... as I understand it the
> lack of a ground plane, lack of proper resonant frequencies, no coil
> load, etc.
>
> Accordingly, what I'd like to hear from a radio-head is what CB
> antenna might be suitable to be used with Vanagon with the goal of
> it being at least better than trying to use a stock OEM antenna, but
> not look too much different from a standard AM/FM antenna (stealth).
> If the antenna looks too much like a CB antenna, the bad guys might
> break it off proactively, or worse, assume that there is a CB inside
> the vehicle that they could steal, and it could be an inducement for
> them to break in.
>
> For all I know, a radio-knowledgeable person would say to just string
> something inside the fiberglass, or make a non-standard flat antenna,
> or some non-traditional design.
>
> For my implementation, I'll either re-use the ancient Autopage
> transmitter I have been using, which transmits at 27.195, or I will
> implement a more modern solution, such as the DIRECTED ELECTRONICS
> 795T or 795W CAR ALARM 3 CHANNEL VIBRATING PAGER (example:
> http://www.amazon.com/DEI-795W-3-CHANNEL-VIBRATING-RECEIVER/dp/B00076WWTY/ref=sr_1_1?ie=UTF8&qid=1323776835&sr=8-1
> or
> http://www.ebay.com/itm/330653062442?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
> )
>
> I provide these links in case anybody else decides that they want to
> be paged if somebody enters their vehicle without their knowledge and
> they want a hint as to how to go about it. The device is simply
> plugged into whatever alarm system is currently in the vehicle, or
> even connected to door-pin operation, so it can operate along side of
> any other alarm system functionality. Be advised that some modern car
> alarms have the ability to transmit an alert to the remote control
> as well (which would be almost a duplicate functionality) and
> manufactures claim up to a mile reception of such a device. However,
> i still want the old functionality to co-exist with the new one,
> provided I eventually implement the new one, for added
> assurance. For the record, other systems one can employ for added
> assurance include Google maps / GPS transmitters (you can look Google
> Maps to see where your rig is), Canadian model extended range car
> alarms, and so-called "telematic" alarms that operate through the
> Internet, effectively providing infinite range.
>
> Last time I tried to come up with a dual/CB AM FM antenna that could
> transmit 50 watts on CB, the only solution I could find was to send
> an OEM antenna out to Sti-Co, a company that specializes in making
> stealth antennas. For $175 (in 1992) they modified my stock Vanagon
> antenna so that the SWR at my transmit frequency of 27.195 was nearly
> 1:1. They did this by putting something on the antenna lead line,
> but not otherwise altering the antenna. I notice that they are still
> alive and well, with a web site and catalog at
> http://www.sti-co.com/wp-content/uploads/2011/03/Stico-Cat-2010-revised-wo-ST-PD-veh.pdf
> ,
> apparently primarily directed toward law enforcement. In any case,
> one option I see there is to NB-HF-DS antenna, which can handle 150
> watts, and which I cannot help imagine would be much more efficient
> than trying to force a Vanagon antenna do the job.
>
> I'd like feedback from people knowledgeable about radio on this
> issue. The argument that was made to me in 1992 was that it was fine
> to use a Vanagon antenna to transmit CB efficiently because the
> antenna only had to be tuned to operate at exactly 27.195 instead of
> having it try to operate on the entire CB band range. In other words,
> the argument was that by having an extremely narrow band antenna, one
> could get away with using a vastly worse CB antenna and get the same
> result as a quality CB antenna. Does this sound right?
>
> I notice that the CB antenna I just named is 36 inches tall, which as
> I understand it is a compatible length for use with CBs. The best
> length for FM antennas is something like 29 to 33 inches, and I
> notice that my OEM antenna here extends 31 inches. So, I think that
> whatever solution is arrived at, it would be best if the antenna were
> 36 inches tall instead of 31, and that the operator would normally
> use the antenna at 31 inches, but extend it out to 36 inches when
> leaving the car and using the alarm functionality.
>
> Does this sound reasonable?
>
> Any ideas about how to go about this?
>
>
>
> _______________________________________________
> Derek Drew
> Washington DC / New York
> derekdrew@derekmail.com
> Email is best normally but...
> PHONE: 202-966-7907 (Call the number at left normally)
> (alt/cell for diligent calling only): 703-408-1532
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