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Re: help! (ao-27)



    Double check your duplexer, make sure it is passing the 2 meter
    signal to the antenna.

>>  If you can't hear your self in the head phones, means you are not
>>  getting into the Satellite.

    You could use more power to step on the other people using the
    bird,  but you would not do that on your local repeater, Would you?

    Hope we get some more like the AO27.

    73 Al Lowe N0IMW 
    Arrow Antenna 

NOT TRUE, at least, not in general.  I worked AO-27 for most of a year
primarily on a mobile quarterwave (and got close to half-way to WAS),
and RARELY heard my own downlink.  I normally hear my own downlink
with an antenna with similar gain characteristics to an Arrow (but
without a diplexer), but the real test is whether people hear me and
respond.  At least on this coast, there are many of us who are always
on the lookout for newcomers and make a point of saying hello.

PLEASE, don't transmit until you hear your own downlink!  That may be a
good idea on a linear transponder such as AO-10, RS-12, RS-15, or FO-2x;
but it just causes QRM on AO-27, and can be a very bad thing.  Do listen
for someone else talking at the same time you're talking.  I hear that
alot more often than my own downlink on crowded passes.  At that point,
you know you're not getting in and you need to wait that station (and/or
those who respond to that station) to finish, so you will be transmitting
when others can hear you.  

If you're not hearing anything in North America, then you probably aren't
hearing the bird (most like it's not the right time, or in the evening,
when AO-27 is asleep). AO-27 is almost always active over North America.
If you can copy callsigns, then you can try transmitting.. But don't hear
your own downlink and you don't hear other stations covering you up, then
there's a decent chance you might still be making into the best.  Listen 
for an answer and maybe try a couple times more during a lull.  If no one
comes back to you, then it's time to check the transmit side. The downlink
is not dependable on some rigs, and many don't receive and transmit at
the same time, even with headphones.  When buying a rig, the latter are to
be avoided for voice satellite work.

If possible, avoid weekends if you're new to AO-27.  On transcontinental
passes, even the regulars have trouble completing contacts sometimes.
To start with, try a weekday pass above 20 degrees.  Don't call CQ, just
briefly give your callsign, with your grid square and/or location.  We'll
be listening for you (and i'll check my recent tapes to see if you were
on when i've been).

				-- KD6PAG

P.S.  Here's what i do to check my own antenna, i choose a weak repeater 
on each band that i know the location of, which i know i can't bring
up with a 'rubber duck', and operate on the lowest power setting.  If i
can bring up the repeater and get a strong signal back, then i know the
antenna is working decently.  

You can also check the gain if there's a step attenuator you can use.
Adjust it with a reference antenna, preferrably a quarterwave ground-
plane (if you want numbers meaninful to others), or a rubber duck if you
just want a comparison.  Pick a strong station that's on most of the time
(or do this during a net).  Adjust the attenuator so it read 4/5 scale on
your HT with the standard antenna.  Write down that measurement.  Point
your test antenna at the repeater (or other signal source), find the max.
and then adjust the attenuator to read the same value.  The difference is
the dB gain of the test antenna vs. the reference one.  If you've used a
quarterwave ground-plane, this will be a reasonable approximation of the
gain in 'dBd' (decibels over a reference dipole).

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