[Yaesu] Re: RX Antenna

[Larry Menzel]

Listers...

Been using the Front End Saver for over a year on my Bevs...I highly
recommend the use of some kind of grounding device, and this little box
(bout $50) really gets the job done well.  Easy to build from kit...I moded
mine with an off-on switch and a power LED.  

I don't recommend using the receive antenna input to your radio without
one...I've seen the disasterous results.  One brand new 775 and several
other radios bit the dust.

Someone post CJ Electronic's address and phone number to the list so others
can get one too.  I'm out of town, or I'd do it myself.

Larry N0XB




At 04:24 PM 12/23/97 -0500, Swanson, Glenn,  KB1GW wrote:
>
>
>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
>
>
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>


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