[Yaesu] Re: RX Antenna

[Swanson, Glenn, KB1GW]

Greetings,

Humm....

Been there, done that.

It's really not as clear a matter as "No" don't worry about it, or "Yes" it 
is a problem.

I'd suggest that the answer is "It depends..."
If you have RF-feedback from your Beverage, then yes, do something about it. 


This can be as simple as wiring in a relay to send the Beverage to ground 
while transmitting, or involve more circuitry, such as the "QSK compatible" 
device called the "Front End Saver" (or, "FES").  See the article, "Beverage 
Antenna's--There's More To Them Than Meets The Eye," in CQ Magazine, 
February 1997.
(I have no experience with, nor can I vouch for, the companies mentioned 
above. :-)

Indeed, for some it's "no," no problem here, yet for others, it's "yes" it 
is a problem.

This seems to (pretty much) depend on the distance (or lack thereof) between 
your TX and RX antennas, I'd say. If you notice a problem (radio folds back 
its output; or radio acts "crazy"), then you need to deal with it:  I'd 
suggest you try to measure the RF coming down the Beverage feedline while 
your transmitting to check things out.

You can use a reasonably-sensitive swr/power meter for this: Beverage 
feedline as the "transmitter," and a dummy load as the "antenna."   How much 
RF (from the Beverage) do you measure when transmitting on the "main" 
160-meter TX antenna?
Start with the 100-W scale and work your way down from there. (I've heard of 
.75 W when transmitting at 100 W, on up to 30 W when transmitting at 1.5 
KW.) It depends.

Or, put a 12v (25ma) bulb in series with the Beverage (or RX loop, or 
whatever else you're using for an auxiliary RX antenna) feedline: Mount two 
RCA plugs on a Radio Shack minibox and solder the bulb leads in between. 
(These bulbs are available where the've "got answers," your local Radio 
Shack. Or do they just have ties on? ;-)

As Lew, K4VX said:
"The bulb will light with less than 1/2 watt of power which is usually not 
enough to do damage, but gives an indication something needs to be done such 
as grounding the Beverage during transmit. The bulb should burn out before 
RX damage would occur (hopefully)!"

Hope this helps, Bill!

Happy Holidays es 73,
Glenn, KB1GW
Connecticut

=================
[Yaesu] RX Antenna

William P. Osborne (wosborne@utdallas.edu)
Mon, 22 Dec 1997 15:49:23 +0000

     Messages sorted by: [ date ][ thread ][ subject ][ author ]
     Previous message: Ron Galbraith: "[Yaesu] FT1000mp for Sale"

If I use a beverage with my 1000MP and connect it to the RX antenna
input do I need to worry about burning up the mp receiver douring TX?

Thanks for the help...Bill, K5ZQ


--
FAQ on WWW:               http://www.qsl.net/k7on/yaesu.html
Submissions:              yaesu@contesting.com
Administrative requests:  yaesu-REQUEST@contesting.com
Problems:                 owner-yaesu@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm