searching advice on low pass filter for 146 MHz
What an amazing responsetime on this list !
(post the question, go shopping, find valuable advice !)
thank you all very much !
It will be a few days, until I can get at the antenna. I will report my findings here
Thanks and
73 Werner, HB9BNK
Werner Kullmann, HB9BNK expunged (hb9bnk@uska.ch):
What an amazing responsetime on this list !
(post the question, go shopping, find valuable advice !)
thank you all very much !
Since you have plenty of gainr, one cheap alternative might be to try a tuned stub inline with the feedline.
-Steve
N1JFU - http://n1jfu.blogspot.com - smeuse@twitter
Hi Steve, N1JFU
A tuned stub 1/4 wave long open to the other end and inline with the feedline will be too large in responce and it will attenuate the same amount of dB both 145.900 MHz and 147.300 MHz
73" de
i8CVS Domenico
----- Original Message ----- From: "Steve Meuse" smeuse@mara.org To: "Werner Kullmann, HB9BNK" hb9bnk@uska.ch Cc: amsat-bb@amsat.org Sent: Wednesday, April 27, 2011 8:35 PM Subject: [amsat-bb] Re: searching advice on low pass filter for 146 MHz
Werner Kullmann, HB9BNK expunged (hb9bnk@uska.ch):
What an amazing responsetime on this list !
(post the question, go shopping, find valuable advice !)
thank you all very much !
Since you have plenty of gainr, one cheap alternative might be to try a
tuned stub inline with the feedline.
-Steve
N1JFU - http://n1jfu.blogspot.com - smeuse@twitter
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
Werner: I EMPHATICALLY agree with the advice to turn down the gain. Improving your IMD will provide much more bang for the effort than trying to find a filter with a loaded Q of over 100 at 2m.
An easy way (if imperfect) to get it "right" is to maximize the RF gain in the Icom radio and then adjust gain down until the preamp-on noise is only SLIGHTLY higher than preamp off. This gets you enough gain to let the preamp set system noise figure, although you still have a bit of excess.
Good luck and please share your results! 73, Jim wb4gcs@amsat.org
On 4/27/2011 1:15 PM, Werner Kullmann, HB9BNK wrote:
What an amazing responsetime on this list !
(post the question, go shopping, find valuable advice !)
thank you all very much !
It will be a few days, until I can get at the antenna. I will report my findings here
Thanks and
73 Werner, HB9BNK _______________________________________________ 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 (4)
-
i8cvs -
Jim Sanford -
Steve Meuse -
Werner Kullmann, HB9BNK