Thanks for your response Fred.
I confess though that I am not sure that I understand all of it. Age is
beginning to effect the clarity of my thinking processes, perhaps in the
same way that my six year old Icom A 200 is not so clear in extreme
circumstances.
I began to lose the thread with the 'wild geese' and 'turkeys', and
something to do with 'doorstops'. I must also confess that I am not totally
up to speed with 'Genave Alpha 360's either, and I am even a little rusty on
'general azimuth'. Other than that, I think I am almost quite clear about
what you are saying.
So, what can I do Fred? Can I chop a bit off somewhere, or do I need a new
radio?
Incidentally, friends have noticed that the transmit performance drops off
when the European Safety Com frequency 135.475MHz is used.
Regards.. Bryan
----- Original Message -----
From: "Fred Fillinger" <n3eu@comcast.net>
Subject: Re: Europa-List: Radio reception problems
>
> <bryan@blackballclub.com>
>>
>> They were receiving me strength five, but for much
>> of the transit I could not hear them at all.
>>
> Antennas work by the rule of reciprocity, and above indicates antenna
> is not the problem, at least in that azimuth of the 360-deg pattern.
>
>> In both cases I have been able to hear other
>> aircraft speaking to them strength five,
>
> If you can't hear a ground station, but other A/C yes, and they're not
> in the same general azimuth, the radiating pattern of the antenna is
> suspect -- an installation location problem. A/C to A/C doesn't have
> the line-of-sight problem like A/C to ground over terrain. But the
> ground station can achieve a near perfect antenna, canceling out the
> line-of-sight issue.
>
>> I can now see that I have a common problem at the lower frequencies,
>
> Receive problems on the extremes of the bands indicate alignment
> problems, but radios just don't go out of alignment to any significant
> degree, if at all. The degree of problem you report suggests a
> component might be way off spec. Low odds, but people hit lotteries.
> Also, radiating pattern problems can be frequency dependent to some
> degree.
>
> Hope this helps rather than chases wild geese!
>
> BTW, we can't deduce strength five or strength anything from what is
> heard, unless rather weak. Leveling circuitry in modern radios +
> other factors. Our old control tower was even handing "strength
> three" or "four" to people. Must have an S-meter I figure. But first
> visit to the tower, I alarmingly saw they used a Genave Alpha 360, a
> "doorstop" in alternative use. No S-meter, but that turkey of a radio
> could actually hint at strength reasonably well.
>
> Reg,
> Fred F.
>
>
>
|