n6gn
About
- Username
- n6gn
- Joined
- Visits
- 5,425
- Last Active
- Roles
- Member
- Points
- 31
Comments
-
I think you were interested in the time constant. Here's what I measure for a falling/rising edge of a longish, very square S9 pulse in AM, 10 kHz bw, X axis is seconds (Image) It looks like things are tailing for a few ten's of ms, not certain th…
-
fbx wrote "Doing so, the min would become closer to the noise floor, and would not require manual tweaking with the slider, and the max would always fit the spectrum view." Should this not be "... farther from the noise floor...&quo…
-
risking some thread drift, I might add that it can be very revealing to process a sample of wideband AM or IQ from a section of spectrum that appears to be 'white' noise, yet elevated above ITU values - which is the case for many if not the vast maj…
-
wsprdaemon is a nice way to get this same information over an entire day. It also plots noise by band which gives even more insight into noise time and other characteristics. Because there are two algorithms, even more information is possible than …
-
I was suggesting a terminated noise test, apart from external antenna or CM on the transmission line. Stock Kiwis tend to have a mid-HF bump while I didn't see that on the BBAI. I slightly suspect it will be pretty good and certainly not an issue i…
-
Thanks for posting. It does make one wonder how it might work were the intervening sheet Copper and perhaps thicker and even lower thermal resistance. Also what would happen if thermal padding were placed between the components or ground plane on e…
-
I agree it's probably not casual listening to USAF Global Comms, I had someone with an IP address associated with St. Petersburg on my Kiwi for some time, repeatedly relogging on when booted. I like Clint's idea...
-
Here's a plot of the two 21m steps in Latitude with the Kalman filter turned off midway between the moves.(Image)
-
Inexpensive GPS receivers do work fine and would perhaps be better for small-area surveying. However I'm now thinking that using a geostationary satellite to provide location data across a typical residence-sized yard is probably not the best way to…
-
Since reporting my experience with administrative GPS access which John kindly added to the kiwiSDR's capabilities, I feel I need to provide an update based on further investigation. With help from G3ZIL it is now clear that the apparent high preci…
-
I think that there is likely not a generic solution, certainly unless you can provide a generic definition of 'noise'. If it's large enough, signal is probably easier but deciding whether noise is an average, peak, what averaging period, power aver…
-
Actually, I think the power has been on the whole time. The issue seems to be a poor quality router that loses its way and no one having access to help it out. There may be plans for a replacement but there is perhaps a little politics in that one.…
-
I know very little about QRSS except that like many of the other narrowband modes it comes in several flavors. I believe it is a fairly simple system in which one can effectively set varying bandwidths by selecting different 'dit' times. I think t…
-
Maybe I misunderstood, but that's not how I understood k5mo's question. What I heard him asking is whether in decoding QRSS in an a communications channel (not the wide Kiwi waterfall) whether additional processing was done by the 'standard' QRSS to…
-
Thanks for adding that John. It seems to work fine and I've been able to look at the on-board GPS's stability. I find it surprisingly good in spite of very poor antenna positioning. Here's a map of 'wander' of a fixed kiwi over an hours' time (Image…
-
Thanks John. That seems to work well. Was the 3 seconds delay to write the file a guess that might be shortened or the result of a measurement? It's probably OK as is, given the GPS positional jitter/wander and how fast I can move the receiving sys…
-
Thanks John. Maybe I'm the only one who wants it in which case adding a separate GPS receiver to the portable system is the right solution. I'd forgotten that publicly available location would be sensitive.
-
It appears that [kiwi_IP}:[kiwi_port]/status only returns the lat/lon from the Webpage tab rather than any value actually read from the GPS. Is there a way to retrieve the GPS's idea of lat/lon when it is present? I'm trying to make a mobile kiwi …
-
I don't doubt the experience of increased noise, I've experienced that as well. I'm just not confident that it is a far-field increase rather than near-field and CM. I suppose a way to separate these is to show, or not, measured galactic noise rela…
-
Thanks for sharing. I'm concerned that most measurements at amateur locations may not be of propagated noise but rather near-field or common mode ingress to the measuring system. I don't have much to back this up except a few tentative measurement…
-
Chris, "very difficult to do via an algorithm" is certainly true! In essence it is this algorithm , this model or theory, I have been trying to achieve during the last few years as I've been working with broadband antenna solutions for th…
-
You have a point about comparisons among different receivers but in examining the results I find the SNR algorithm to be a very poor reflector of station performance. The best WSPR stations with Kiwis don't necessarily rank well at all. A station wi…
-
It does if you live in Fort Collins :) :) (Image)
-
Funny, the first post I see is from Powernumpty with no reference to instructions: "Kiwi BBAI software Alpha test instructions Powernumpty February 6 Thanks that would work. I was sort of looking for a command I could run for …
-
I've successfully updated the BBAI and built the kiwiSDR code. Initially the kiwi build complained but manually running the 'clang' line worked and a second try resulted in a running SDR. I'm now working on cooling along the lines of @iw2nke. Howe…
-
Thank you IW2NKE for the measurements and data. This fits the thought that "a little bit of air flow goes a long way". I just acquired a BBAI/kiwi (my 5th kiwi) and will be embarking on bring it up before long. In reading experiences a…
-
I'm finding that "it works sometimes". I managed to get it not work, QSYed to a ham band where it worked, fussed around after which it quit. Maybe someone else can figure out the conditions for (non)working.
-
Matt, N0RGT, one of the (I think) three who regularly man all 7 of the Fort Collins NIST transmitters, WWVB and the six HF WWVs, put 25 MHz back on the air in 2014 http://www.arrl.org/news/wwv-s-25-mhz-signal-back-on-the-air The 25 MHz antenna is a…