Comments for Rowetel http://www.rowetel.com/blog open telephony software and hardware Thu, 13 Jun 2013 05:12:30 +0000 hourly 1 http://wordpress.org/?v=3.0 Comment on Fox Hunting and Ham Radio as Therapy by Mel Whitten, K0PFX http://www.rowetel.com/blog/?p=3019#comment-69983 Mel Whitten, K0PFX Thu, 13 Jun 2013 05:12:30 +0000 http://www.rowetel.com/blog/?p=3019#comment-69983 Looks like you had fun.. oh yes, pine trees.. terrible, especially what they do to RF in the 400mhz or so range. Mel Looks like you had fun.. oh yes, pine trees.. terrible, especially what they do to RF in the 400mhz or so range.

Mel

]]> Comment on Flukso – Wifi Household Power Logging by bazzle http://www.rowetel.com/blog/?p=135#comment-69967 bazzle Sat, 08 Jun 2013 05:08:23 +0000 http://www.rowetel.com/blog/?p=135#comment-69967 Hi David Are you selling the FL02B yet? Bazzle Hi David

Are you selling the FL02B yet?

Bazzle

]]> Comment on Flower Pot Antenna and Wifi Sleeve Dipoles by Naresh http://www.rowetel.com/blog/?p=1728#comment-69932 Naresh Thu, 16 May 2013 20:09:08 +0000 http://www.rowetel.com/blog/?p=1728#comment-69932 Hi David, Very interesting article. Suppose one made an S or a loop in the bottom half of the antenna, do you have an idea how its performance would change? My interest is in figuring out how could make a 121.5Mhz (aviation comm antenna) in a small space. best regards, Naresh Hi David,

Very interesting article. Suppose one made an S or a loop in the bottom half of the antenna, do you have an idea how its performance would change?

My interest is in figuring out how could make a 121.5Mhz (aviation comm antenna) in a small space.

best regards,
Naresh

]]> Comment on FreeDV Robustness Part 3 by Anonymous Coward http://www.rowetel.com/blog/?p=2965#comment-69674 Anonymous Coward Thu, 04 Apr 2013 08:42:07 +0000 http://www.rowetel.com/blog/?p=2965#comment-69674 Drive-by comment: Why are you usingGolay code? It's optimal _if_ you don't know which bits are corrupted. Judging from your pictures, this is certainly false: you know what bits are reliable and which are not. You may want to use some codes which can use information about which bits are unreliable (e.g. turbo codes). Rolling your own codes would be best of course. :) Drive-by comment: Why are you usingGolay code? It’s optimal _if_ you don’t know which bits are corrupted. Judging from your pictures, this is certainly false: you know what bits are reliable and which are not. You may want to use some codes which can use information about which bits are unreliable (e.g. turbo codes). Rolling your own codes would be best of course. :)

]]> Comment on FreeDV by david http://www.rowetel.com/blog/?p=2782#comment-68922 david Wed, 27 Mar 2013 20:11:12 +0000 http://www.rowetel.com/blog/?p=2782#comment-68922 Sorry, building in Linux still often requires manual tweaks. Im hoping some one will step in and fix this. Sorry, building in Linux still often requires manual tweaks. Im hoping some one will step in and fix this.

]]> Comment on FreeDV by Jason Fox KB3LMS http://www.rowetel.com/blog/?p=2782#comment-68885 Jason Fox KB3LMS Wed, 27 Mar 2013 12:00:40 +0000 http://www.rowetel.com/blog/?p=2782#comment-68885 Wow, sounds like a neat application. I read about it in QST this month. Been trying to build from source on Ubuntu 12.10 with no luck. (Can't read symbols from libasound.so ????) Is there a PPA or deb available anywhere? Wow, sounds like a neat application. I read about it in QST this month. Been trying to build from source on Ubuntu 12.10 with no luck. (Can’t read symbols from libasound.so ????) Is there a PPA or deb available anywhere?

]]> Comment on FreeDV Robustness Part 3 by john http://www.rowetel.com/blog/?p=2965#comment-68605 john Sun, 24 Mar 2013 21:25:27 +0000 http://www.rowetel.com/blog/?p=2965#comment-68605 Hi, HP developed a measurement called EVM, error vector magnitude. I am not sure of the math involved, but I think it would be good to have the receiver compute and display it so the transmitter can be monitored and adjusted. And also the receiver path can also be optimized. John Hi,

HP developed a measurement called EVM, error vector magnitude. I am not sure of the math involved, but I think it would be good to have the receiver compute and display it so the transmitter can be monitored and adjusted. And also the receiver path can also be optimized.

John

]]> Comment on Coherent PSK Demodulation on HF by david http://www.rowetel.com/blog/?p=2815#comment-68398 david Fri, 22 Mar 2013 20:06:32 +0000 http://www.rowetel.com/blog/?p=2815#comment-68398 Thank you that's good to know if I revisit this area again Thank you that’s good to know if I revisit this area again

]]> Comment on Coherent PSK Demodulation on HF by Dr Olubodun http://www.rowetel.com/blog/?p=2815#comment-68358 Dr Olubodun Fri, 22 Mar 2013 12:45:58 +0000 http://www.rowetel.com/blog/?p=2815#comment-68358 I have implemented a similar comparison via 40Gbps systems using GNLSE library C++ software and in my results there was ~2dB improvement in performance of the coherent PSK system DPSK system. the performance improvement was constant for different received bandwidths and SNR. I have implemented a similar comparison via 40Gbps systems using GNLSE library C++ software and in my results there was ~2dB improvement in performance of the coherent PSK system DPSK system. the performance improvement was constant for different received bandwidths and SNR.

]]> Comment on FreeDV by Richard K8NDS http://www.rowetel.com/blog/?p=2782#comment-68053 Richard K8NDS Wed, 20 Mar 2013 01:46:18 +0000 http://www.rowetel.com/blog/?p=2782#comment-68053 What kind on processor power is necessary for stable operation? I would run Linux for sure. Tnx, Rich K8NDS What kind on processor power is necessary for stable operation?
I would run Linux for sure.

Tnx,
Rich
K8NDS

]]>