Topband: fixing beverage

[donovanf at starpower.net]

A Time Domain Reflectometer is one of the best tools to verify 
the proper performance and isolate faults of a Beverage and many 
other types of antennas. 


In the case of a Beverage, the TDR allows you to see every 
component of the antenna system from the ham shack all the way 
to the termination resistor. If anything fails you can almost 
always walk directly to it with the needed replacement parts and 
tools in hand. 


73 
Frank 
W3LPL 

----- Original Message -----

From: "Jorge Diez - CX6VM" <cx6vm.jorge at gmail.com> 
To: "TopBand List" <topband at contesting.com> 
Sent: Monday, November 23, 2015 8:29:15 PM 
Subject: Re: Topband: fixing beverage 

Thanks all you guys for the help 

Will do this tests and see what is wrong 

73, 
Jorge 
CX6VM/CW5W 

-----Mensaje original----- 
De: Tom W8JI [mailto:w8ji at w8ji.com] 
Enviado el: lunes, 23 de noviembre de 2015 02:35 p.m. 
Para: Jorge Diez - CX6VM; 'TopBand List' 
Asunto: Re: Topband: fixing beverage 

> 
> I notice that my USA beverage is lower in 3-4 S units that some weeks ago. 
> 

5-20 dB. Depending on receiver and where it is at on the S meter. 

That has to be a poor connection, open, or short between the receiver and the Beverage transformer end of the Beverage. It cannot be at the termination end. 


> At simple view all seems to be OK. I think the coax is not the 
> problem, because if I have a problem in the coax, will be completely deaf, right? 

No. Coax can do this. It happens all the time. Especially at connectors. 

> 
> So this can be the cause of a problem in the end resistor or maybe in 
> the transformer? I use in this beverage a WX0B beverage boxes 
> 

It can not be at the end resistor termination. 

The problem is if you disturb something it will often start working. You need to carefully check one thing at a time. Many times, if not most times, this is corrosion or tarnish on the center pin of the coax. Sometimes it is a broken wire, or a bad part from lightning or water. 

The best way to test it is with an SWR meter and do a frequency sweep from the house, before you touch the antenna or any outside connections. The frequency of either adjacent major dips in SWR or impedance will allow you to calculate exactly where the problem is. The MFJ analyzer will do this within a few feet, even on a 1000 foot cable, by using distance to fault. 

73 Tom 


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