T&T: VHF Antenna Question

[Milt Baker]

FYI, here's what I received from Digital Antenna a bit more than 24 hours 
after posting my problem with on the DA website.  My response follows.

--Milt


===================

> Milt,
> 
> Everyone at Digital Antenna is very attentive to returning inquiries.
> During busy times replies may take up to 24 hrs especially during trade
> show time.  
> 
> An 8' antenna can outperform a 16' antenna in certain situations. A 16'
> higher gain antenna is for long range communication and may overshoot a
> close signal where the 8' antenna has a lower radiation pattern and can
> pick up a closer signal; thus the reason for having two antennas of
> different height and gain on the boat.
> 
> To test performance and installation, go out to sea and the 16' VHF
> should out distance the 8' VHF. 
> 
> Another area to examine is the mounting of the 16' VHF. The 16' VHF must
> be clear of all metal by 3'. If the 16' VHF antenna is close to metal it
> may de-tune.
> 
> We test every antenna before leaving our facility. Each antenna is
> precision tuned. It is highly unlikely and almost impossible that two
> 16' VHF antennas would be defective. 
> 
> It is important to choose the proper antenna for each installation. It's
> possible that you may be better suited with an 8' VHF on top of an
> extender depending on your mounting options. Your dealer should be able
> to determine which type of antenna to use.  
> 
> Best Regards,
> Al White
> Technical Sales and Support
> support@digitalantenna.com
> www.digitalantenna.com

====================

Al,

Thank you for your e-mail.  I don't mean to be confrontational, but it definitely 
is off-putting when a customer is told that tech support is not for customers but 
for dealers only, then to have to wait more than 24 hours for a response.  

To the points you made:

	--When I said the the 6 DB gain antenna outperformed the taller 
9 DB gain antenna by 50%, I noted that it was not a nearby station that we 
used as a yardstick but, rather, we  judged it by bringing in a weak and distant 
station--we used a NOAA weather station many miles from the boat's location.  
Both the 6 and the 10 perform fine with nearby stations. 

	--In the last year, I traveled over 8,500 NM with this boat (Florida 
to Venezuela to Bermuda to New England to Florida) using both the 16-footer 
and the 8-footer.  Consistently the 8-footer out-performed the taller antenna.  
That's why I said in my initial post that it appeared to me that something had 
gone wrong with the taller antenna, so we purchase a new model 532 WV-R 
gain antenna and tried it but received identical results.  It does not seem to 
matter: at sea and in port, the performance of the taller antenna is poorer 
than that of the shorter one.  

	--If the two antennas are not defective, can you tell me why they 
are not performing like they should?  If nothing else, clearly a taller antenna 
should receive more distant stations than a shorter one, assuming both are 
mounted at the same level (they are) and all else is identical (it is as far as 
much tech and I can determine).

	--As a consuimer, where do I go from here?
	
By the way, I failed to mention that we tested the VSWR of all three antennas 
and found it perfect.

Standing by,

--Milt Baker, Nordhavn 47 Bluewater, Fort Lauderdale	

==============================

Al,

Sorry, but one point you raised that I failed to address:

	--Nearby metal: none of these antennas is closer than 10 feet to any 
metal other than rigging wire.  When we tested the new 16-footer, we moved it 
around to several locaions on top of the pilot house with no noticeable change in 
reception.

Thanks,

--Milt