On the premise that the only dumb question is the one that goes unasked, here goes.
If I'm building an antenna of circular polarization for use with the birds what determines if it should be LHCP or RHCP? I've read the ARRL Satellite Handbook and "sort of" searched the AMSAT-BB archives but found nothing about this question.
Thanks. Tom - K0TW
Tom, if you go with just RHCP you should be ok.
73 de Sebastian, W4AS
On Oct 5, 2010, at 7:23 PM, Tom wrote:
On the premise that the only dumb question is the one that goes unasked, here goes.
If I'm building an antenna of circular polarization for use with the birds what determines if it should be LHCP or RHCP? I've read the ARRL Satellite Handbook and "sort of" searched the AMSAT-BB archives but found nothing about this question.
Thanks. Tom - K0TW
Hi Tom-The vague answer is " it depends". I have found that different polarizations are more effective on the same satellite during the same pass at different times. Why that happens? I have no idea, the answer to that is out of my pay grade. I have a L & R switches and they get used a fair amount. I am sure everyone else's mileage will vary. This has been my experience.
73 Bob W7LRD
Seattle
----- Original Message ----- From: "Tom" k0tw@cox.net To: amsat-bb@amsat.org Sent: Tuesday, October 5, 2010 4:23:46 PM Subject: [amsat-bb] LHCP or RHCP?
On the premise that the only dumb question is the one that goes unasked, here goes. If I'm building an antenna of circular polarization for use with the birds what determines if it should be LHCP or RHCP? I've read the ARRL Satellite Handbook and "sort of" searched the AMSAT-BB archives but found nothing about this question. Thanks. Tom - K0TW _______________________________________________ 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 Tom,
Is your question:
How do you determine the resulting polarity of the anteanna?
My response: when standing at the rear, does the cork-screw go clockwise or counter-clockwise as it spirals away from you? That is the visible difference, if building a helix.
OR
Which polarity should I build?
Here's my take--if you can't do both polarities and switch, you may be better of going linear. But if you have to build circular, you are probably better off with RHCP if you work 435.300 on AO-51 a good deal...
Keep in mind that 435.150 is LHCP--so when we run QRP or JOTA mode this month, you fixed RHCP folks are going to see what I mean....
73,
Mark N8MH
On Tue, Oct 5, 2010 at 7:23 PM, Tom k0tw@cox.net wrote:
On the premise that the only dumb question is the one that goes unasked, here goes.
If I'm building an antenna of circular polarization for use with the birds what determines if it should be LHCP or RHCP? I've read the ARRL Satellite Handbook and "sort of" searched the AMSAT-BB archives but found nothing about this question.
Thanks. Tom - K0TW _______________________________________________ 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 Tom, K0TW
In a separate email I have sent to you what in my opinion is the best and easy to understand article about the use of circular polarization written by K4KJ "The advantages of circular polarization"
If anybody is interested on it please let me know.
73" de
i8CVS Domenico
----- Original Message ----- From: "Tom" k0tw@cox.net To: amsat-bb@amsat.org Sent: Wednesday, October 06, 2010 1:23 AM Subject: [amsat-bb] LHCP or RHCP?
On the premise that the only dumb question is the one that goes unasked, here goes.
If I'm building an antenna of circular polarization for use with the birds what determines if it should be LHCP or RHCP? I've read the ARRL Satellite Handbook and "sort of" searched the AMSAT-BB archives but found nothing about this question.
Thanks. Tom - K0TW _______________________________________________ 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 Tom, K0TW
In a separate email I have sent to you what in my opinion is the best and easy to understand article about the use of circular polarization written by K4KJ "The advantages of circular polarization"
If anybody is interested on it please let me know.
73" de
i8CVS Domenico
----- Original Message ----- From: "Tom" k0tw@cox.net To: amsat-bb@amsat.org Sent: Wednesday, October 06, 2010 1:23 AM Subject: [amsat-bb] LHCP or RHCP?
On the premise that the only dumb question is the one that goes unasked, here goes.
If I'm building an antenna of circular polarization for use with the birds what determines if it should be LHCP or RHCP? I've read the ARRL Satellite Handbook and "sort of" searched the AMSAT-BB archives but found nothing about this question.
Thanks. Tom - K0TW _______________________________________________ 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
participants (5)
-
Bob- W7LRD -
i8cvs -
Mark L. Hammond -
Sebastian -
Tom