[amsat-bb] Re: S band and Eagle: an appeal for a higher level discussion

Luc Leblanc VE2DWE lucleblanc6 at videotron.ca
Sat Sep 9 03:22:36 PDT 2006

On 8 Sep 2006 at 1:04, Tom Clark, K3IO wrote:

> Yes, this decision was based on incomplete data. It would be wonderful
> if many of you took the challenge to make quantitative measurements of
> the S-band RFI levels in multiple locations. Just take your S-band LNA,
> put on a low-gain antenna and measure the difference in background noise
> level between that antenna and a 50 ohm dummy load as accurately as you
> can. You will get better accuracy if you can  use a wide measurement
> bandwidth (10-100 kHz or so). Remember to disable your receiver's AGC. A
> good spectrum analyzer would be an excellent choice to use as the
> detector. Please feel free to send me any such measurements along with
> notes on the equipment you used and the environment where you made the
> tests (urban, rural, etc). My Email address is mailto:K3IO at verizon.net.

As we are surrounding by engineers (a necessary sickness in this new century) Joke!
the test Tom Clark propose is challenging. A PCR 1000 can do the job i think. If time permit this 
week end i will try the test.

There is a lot of jokes about engineers here as when something goes wrong it is never due to their 
work but it is in the application of their plans... The fist thing they learn is to never used the 
word error or when they fart it always smell rose. 

You know i make a couple of QSO on AO-51 last week on the V/S mode with the same set up i was using 
on AO-40 i remember where the noise level was in 2003 and i also remember the nature of this QRM 
Pop Pop hiss swishing sound and son on. What i remark different was the poping sound, there was 
more pops than 3 years ago! but they seems to conteract between them. (the has been perform in SSB 
not in FM)

The antenna was pointing at the horizon but as soon as i elevated the antenna the noise drastically 
reduce to a point where i am sure AO-40 phone QSO will be possible (If he was there...)

In my town we have one 2 lane highway. In the Washington area i have on in mind the 395 the belt 
way as they called it if i'm remembered correctly. i can assume the traffic is matching accordingly 
with the highways as the noise level in both places.

It's cute to see a lot of calculus to tell us the S band is unusable but why i try to switch in CW 
at LOS with a 2 degree elevation playing with the DSP settings in a way to make this rare one 
buried in the noise and the pop pop QRM from the cordless phone? Why i do this if the calculus told 
me i cannot hear anything?

This story happens 3 years ago and the station was a VU and this one give me my WAC satellite 
endorsement (Hope to get it soon..)

I am not an engineers but an amateur radio operator read my lips here AMATEUR take out your 
dictionary and check the definition. A ham work in a QRM QRN interference world and it was what i 
experience since 1971.

Will i be able to do the same when P3E and Eagle will eventually be in space i answer yes, is the S 
band will be as noise as of today no as when i make my SSB test i scan from 2.1 to 2.7 ghz and all 
the analog phone seems to vanish i repeat the test at a couple of time at different hours and there 
is no more analog phone around!

Yes my wife microwave oven still bothers me (It is my microwave oven when i used it:) but a lot of 
QRM disappear remains the frequency hoping phones but most of the traffic on satellite is often 
done at night or in the evening where the phones are less uses.

Bottom line i will posted my results with Tom test.

The medium is the message...The content is the audience...;)

Luc Leblanc VE2DWE
Skype VE2DWE

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