Hello
I built a 10 turn helix for 435 MHz.
I have 15 meters of RG-213.
Radio is an ICOM 706 mkii G
I am not getting strong signals like I would have expected ?
Can someone share their setups and signal strengths ?
Maybe a pre-amp might help ?
Am I getting too much loss in the cable ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC [email protected] http://www.tech-software.net
The RG-213 loss should be less than 3dB if I remember correctly, I think you're okay there. Did you twist the helix the right direction?
jeff
Andrew Rich wrote:
Hello
I built a 10 turn helix for 435 MHz.
I have 15 meters of RG-213.
Radio is an ICOM 706 mkii G
I am not getting strong signals like I would have expected ?
Can someone share their setups and signal strengths ?
Maybe a pre-amp might help ?
Am I getting too much loss in the cable ?
Andrew Rich VK4TEC [email protected] http://www.tech-software.net
Sent via [email protected]. 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
Does ao-51 have circular ?
I have LHCP on my antenna
---------------------------------------------------------------------------- Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: Jeff Mock [mailto:[email protected]] Sent: Friday, 21 December 2007 9:16 PM To: [email protected]; [email protected] Subject: [SPAM] Re: [amsat-bb] AO51 Signals Importance: Low
The RG-213 loss should be less than 3dB if I remember correctly, I think you're okay there. Did you twist the helix the right direction?
jeff
Andrew Rich wrote:
Hello
I built a 10 turn helix for 435 MHz.
I have 15 meters of RG-213.
Radio is an ICOM 706 mkii G
I am not getting strong signals like I would have expected ?
Can someone share their setups and signal strengths ?
Maybe a pre-amp might help ?
Am I getting too much loss in the cable ?
--
Andrew Rich VK4TEC [email protected] http://www.tech-software.net
Sent via [email protected]. 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
AO-51 is LHCP on 435.150, RHCP on 435.300, and linear on 2401.200. If your helix is LHCP and you are listening to the .300 voice downlink, you are in the neighborhood of 20db down from a RHCP helix.
73, Drew KO4MA
----- Original Message ----- From: "Andrew Rich" [email protected] To: "Jeff Mock" [email protected]; [email protected] Sent: Friday, December 21, 2007 6:20 AM Subject: [amsat-bb] Re: [SPAM] Re: AO51 Signals
Does ao-51 have circular ?
I have LHCP on my antenna
Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: Jeff Mock [mailto:[email protected]] Sent: Friday, 21 December 2007 9:16 PM To: [email protected]; [email protected] Subject: [SPAM] Re: [amsat-bb] AO51 Signals Importance: Low
The RG-213 loss should be less than 3dB if I remember correctly, I think you're okay there. Did you twist the helix the right direction?
jeff
Andrew Rich wrote:
Hello
I built a 10 turn helix for 435 MHz.
I have 15 meters of RG-213.
Radio is an ICOM 706 mkii G
I am not getting strong signals like I would have expected ?
Can someone share their setups and signal strengths ?
Maybe a pre-amp might help ?
Am I getting too much loss in the cable ?
--
Andrew Rich VK4TEC [email protected] http://www.tech-software.net
Sent via [email protected]. 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
Sent via [email protected]. 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
Thats interesting about the affect of wrong polarisation - 20dB
According to my other info here that is about S4 to S7 difference.
---------------------------------------------------------------------------- Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: Andrew Glasbrenner [mailto:[email protected]] Sent: Saturday, 22 December 2007 12:44 AM To: [email protected]; [email protected] Subject: [SPAM] Re: [amsat-bb] Re: [SPAM] Re: AO51 Signals Importance: Low
AO-51 is LHCP on 435.150, RHCP on 435.300, and linear on 2401.200. If your helix is LHCP and you are listening to the .300 voice downlink, you are in the neighborhood of 20db down from a RHCP helix.
73, Drew KO4MA
----- Original Message ----- From: "Andrew Rich" [email protected] To: "Jeff Mock" [email protected]; [email protected] Sent: Friday, December 21, 2007 6:20 AM Subject: [amsat-bb] Re: [SPAM] Re: AO51 Signals
Does ao-51 have circular ?
I have LHCP on my antenna
--
Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: Jeff Mock [mailto:[email protected]] Sent: Friday, 21 December 2007 9:16 PM To: [email protected]; [email protected] Subject: [SPAM] Re: [amsat-bb] AO51 Signals Importance: Low
The RG-213 loss should be less than 3dB if I remember correctly, I think you're okay there. Did you twist the helix the right direction?
jeff
Andrew Rich wrote:
Hello
I built a 10 turn helix for 435 MHz.
I have 15 meters of RG-213.
Radio is an ICOM 706 mkii G
I am not getting strong signals like I would have expected ?
Can someone share their setups and signal strengths ?
Maybe a pre-amp might help ?
Am I getting too much loss in the cable ?
-
--
Andrew Rich VK4TEC [email protected] http://www.tech-software.net
Sent via [email protected]. 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
Sent via [email protected]. 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
It is more striking than that because if you are starting with an SNR of 2-3 dB that buries your signal totally (i.e. a minus S4; meter don't bend in that direction). With V and H polarity you will never be more than -3 dB (half an S-unit) down.
Ed - KL7UW
At 06:50 AM 12/21/2007, Andrew Rich wrote:
Thats interesting about the affect of wrong polarisation - 20dB
According to my other info here that is about S4 to S7 difference.
Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: Andrew Glasbrenner [mailto:[email protected]] Sent: Saturday, 22 December 2007 12:44 AM To: [email protected]; [email protected] Subject: [SPAM] Re: [amsat-bb] Re: [SPAM] Re: AO51 Signals Importance: Low
AO-51 is LHCP on 435.150, RHCP on 435.300, and linear on 2401.200. If your helix is LHCP and you are listening to the .300 voice downlink, you are in the neighborhood of 20db down from a RHCP helix.
73, Drew KO4MA
----- Original Message ----- From: "Andrew Rich" [email protected] To: "Jeff Mock" [email protected]; [email protected] Sent: Friday, December 21, 2007 6:20 AM Subject: [amsat-bb] Re: [SPAM] Re: AO51 Signals
Does ao-51 have circular ?
I have LHCP on my antenna
--
Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: Jeff Mock [mailto:[email protected]] Sent: Friday, 21 December 2007 9:16 PM To: [email protected]; [email protected] Subject: [SPAM] Re: [amsat-bb] AO51 Signals Importance: Low
The RG-213 loss should be less than 3dB if I remember correctly, I think you're okay there. Did you twist the helix the right direction?
jeff
Andrew Rich wrote:
Hello
I built a 10 turn helix for 435 MHz.
I have 15 meters of RG-213.
Radio is an ICOM 706 mkii G
I am not getting strong signals like I would have expected ?
Can someone share their setups and signal strengths ?
Maybe a pre-amp might help ?
Am I getting too much loss in the cable ?
--
Andrew Rich VK4TEC [email protected] http://www.tech-software.net
Sent via [email protected]. 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
Sent via [email protected]. 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
Sent via [email protected]. 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
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep [email protected] ======================================
Hi Andrew,
I built a 10 turn helix for 435 MHz.
I have 15 meters of RG-213.
Radio is an ICOM 706 mkii G
I am not getting strong signals like I would have expected ?
Can someone share their setups and signal strengths ?
Maybe a pre-amp might help ?
Yes, the first thing to try is a pre-amp. AT THE ANTENNA!!
Or add turns to the helix, helps some...
Hope you are using "N" connectors, and if the coax is not fairly new, new coax....
That should do the trick.
If not build a quadrifilar....I've checked it vs a 16 turn helix, and the quad was better.
Plans to build one at:
http://home.san.rr.com/doguimont/uploads
Buy everything new, and the connector is the most expensive part!!
Ordinary hand tools will do it easily...
73, Dave, WB6LLO [email protected]
Disagree: I learn....
Pulling for P3E...
participants (5)
-
Andrew Glasbrenner -
Andrew Rich -
Dave Guimont -
Edward Cole -
Jeff Mock