------------ ORIGINAL MESSAGE ------------(may be snipped)
On Sun, 6 Mar 2016 21:26:21 -0600, Michael, KT5MR wrote:
>
>My Yaesu FT-950 has two pre-amp settings.
REPLY:
I read this in the ARRL handbook 50 years ago and it still holds true
today: With the antenna disconnected, observe the background noise
level. With any modern receiver it should be very low. Then connect
the antenna and observe the noise increase. The background noise
should increase significantly, and if it does you don't need a preamp.
What is "significantly"? Well, if you have to listen carefully to hear
the increase, you probably do need a preamp. If it jumps out at you,
you don't.
If you're not sure you can always verify this empirically. Find a weak
RTTY signal and switch the preamp in and out. Does the print improve
either way? There's your answer. If there is no difference, leave the
preamp off. This will help prevent overload from nearby strong signals
While we're talking about receiver settings, the question sometimes
arises about AGC speed. Fast, medium or slow? For a continuous carrier
mode like RTTY, AM or FM, use fast. When the carrier takes a quick
fade, you want the AGC to follow quickly. Medium and slow are fine for
CW and SSB.
Welcome to RTTY. Hope to see you on the air!
73, Bill W6WRT
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|