Currently I have my LNBlock downconverter mounted at the antenna.
It is a High Sierra Microwave 432M7.
The antenna is a Uhf Ringo ranger set at the boiiom end of the band.
It is 25 feet up right now.
So, how do I realize more signal level?
Using my FT-950, both preamps on I can hear signals well.
I have about 75 feet of RG-8X coax at the output of the converter to my shack.
The test paper shows 25 DB gain. I expect this has to be on the UHF side.
I am thinking of a "eggbeater style" antenna to start with and then some hieght for that.
Passes are doing well to the horizon.
Looking forward to feedback.
73,
Alan
Hi Alan,
To answere your question it is necessary to know the following data:
1) Gain in dBi and polarization of your antenna UHF Ringo ranger set.
2) Noise Figure NF in dB and gain in dB of your LNB High Sierra Microwave 432M7 downconverter.
3) Value in MHz of the IF of your 432M7 downconverter.
Having the above data it is possible to compute if it necessary or not to put a 70 cm Low Noise preamplifier between the antenna and the input of downconverter or to use an antenna with greater gain but rotatable in Azimuth and Elevation.
BTW not rotatable antennas like the "eggbeater style" or your UHF "Ringo ranger set" have poor performance for LEO satellite operation if compared with a simple 10 dBi horizontally polarized Yagi antenna rotatable only in Azimuth and fixed Elevation of 20 degrees as often recommended for LEO satellites by Bob, WB4APR on AMSAT-BB
73" de
i8CVS Domenico
----- Original Message ----- From: "Alan Beck" becka@eastlink.ca To: amsat-bb@amsat.org Sent: Monday, May 28, 2012 1:53 PM Subject: [amsat-bb] expections
Currently I have my LNBlock downconverter mounted at the antenna.
It is a High Sierra Microwave 432M7.
The antenna is a Uhf Ringo ranger set at the boiiom end of the band.
It is 25 feet up right now.
So, how do I realize more signal level?
Using my FT-950, both preamps on I can hear signals well.
I have about 75 feet of RG-8X coax at the output of the converter to my
shack.
The test paper shows 25 DB gain. I expect this has to be on the UHF side.
I am thinking of a "eggbeater style" antenna to start with and then some
hieght for that.
Passes are doing well to the horizon.
Looking forward to feedback.
73,
Alan _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hi Alan,
It's not clear to me what your problem is since you said you are hearing signals. Are you not hearing signal with the HSM 432M7?
The High Sierra Microwave 432M7 has a noise figure of less than 1 dB. Check your data sheet and it should likely be around 0.6 dB. The gain of 25 dB is overall gain. This should be more than adequate to over come the 75 feet of coax between it and the FT-950 and to set the "system" noise floor. So you don't need, or want, a LNA ahead of the converter.
You have located the downconverter at the best spot, right at the antenna, but you didn't mention how you were getting power up the 75 feet of coax to the converter.
Regards...Bill - N6GHz High Sierra Microwave www.hsmicrowave.com
On 5/28/2012 4:53 AM, Alan Beck wrote:
Currently I have my LNBlock downconverter mounted at the antenna.
It is a High Sierra Microwave 432M7.
The antenna is a Uhf Ringo ranger set at the boiiom end of the band.
It is 25 feet up right now.
So, how do I realize more signal level?
Using my FT-950, both preamps on I can hear signals well.
I have about 75 feet of RG-8X coax at the output of the converter to my shack.
The test paper shows 25 DB gain. I expect this has to be on the UHF side.
I am thinking of a "eggbeater style" antenna to start with and then some hieght for that.
Passes are doing well to the horizon.
Looking forward to feedback.
73,
Alan _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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Alan Beck -
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