ka7oei
About
- Username
- ka7oei
- Joined
- Visits
- 1,297
- Last Active
- Roles
- Member
- Points
- 2
Comments
-
Thank you all for the answers - I hadn't really dug around in the directories to find "unused" graph data (even the "old" band data files seem to have had been accessed by the system recently) - but this just goes to prove the ol…
-
I recently did some work at the Northern Utah WebSDR to fix a signal path issue on the KiwiSDR that had been excessively attenuating signal below 1 MHz and have consequently restored its ability to hear the band's noise floor on 630 meters (2200 sti…
-
For a Kiwi at Northern Utah WebSDR, I did this, which you may see by going to http://sdrutah.org/kiwisdr1.htm I tried to copy the html here, but it got "munched" by this message board so you will have to look at the above link, yourself.…
-
In the past I have checked the calibration of the noise graphs by placing a CW carrier of known amplitude within the WSPR passband. It's been a while, so I don't recall the details, but I do know that a persisting CW carrier can have a similar effe…
-
I noticed a "problem" that puzzles me: On around the 27th of October, I noticed that the "KA7OEI-1" WSPR reports from the Northern Utah WebSDR system disappeared from both the KB9AMG and WA2ZKD statistics (I only checked those t…
-
With the recent change (1.337) I notice that the noise graphs at the Northern Utah WebSDR (KA7OEI-1) on Grafana and WSPRDaemon.org have shifted upwards (noisier) by between 4 and 5dB. I presume that this has something to do with the change in the m…
-
While you have probably checked this, I had problem when in the gain offset, I didn't use exactly the same name as that used in the receiver definition - but once I fixed that, all of the offsets started to work properly - and still do. Clint KA7OEI
-
The action of the noise blanker, by necessity, causes distortion and the generation of spurious spectral energy. In the ideal situation, its action is "infrequent" , acting only on the "occasional" spike that comes into the ante…
-
As mentioned a while ago, I had the problem of KiwiSDRs not being able to get GPS sync - if, for example, a software update had occurred - while it was "busy" with Kiwirecorder sessions: The instant those sessions were dropped, the Kiwi w…
-
No, not at all: Many people using KiwiSDRs (including me) have dynamic IP addresses that may change occasionally. As long as the Kiwi "knows" its IP address and can convey this to sdr.hu, it will be able to register itself.
-
Although it is getting to be a bit dated - and is catered mostly toward use for WSPR decoding, there is this: http://ka7oei.blogspot.com/2018/10/a-quick-and-probably-incomplete-guide.html This may help you install Kiwirecorder, but not much about …
-
FWIW, I attacked this problem with the much lower-performance RTL-SDR dongles (8 bit A/D converters) - and you may read about that here: https://ka7oei.blogspot.com/2019/04/applying-outboard-agc-in-front-of-rtl.html This is being applied on the 90…
-
It's worth mentioning that at a quiet location, even a KiwiSDR connected directly to a (nominally) unity-gain antenna is not quite sensitive enough to hear the IRU-defined noise floor - much less if it is split several ways. What this means is that…
-
When I added FM to the mcHF, the de-emphasis and filtering (for standard NBFM) consisted of two parts: - Integration to effect a roll-off of 6dB/octave with a "knee" at 300-ish Hz. - Differentiation to effect a high-pass with a low-freque…
-
As the operator of the Northern Utah WebSDR, I've always made it a point to make sure that the S-meter reading reflects the signal at the main antenna port for any receiver, +/-1dB in the middle of the passband. Because the most heavily-used receiv…
-
With power supplies: If, by its heft, you can believe there to be an iron block inside, it's a transformer type. If it feels like it's (mostly) empty, it's a switching type. If its AC input voltage rating is something like "100-240 volts&quo…
-
Question/comment: At the Northern Utah WebSDR site (ka7oei-1 on WSPRNET) we have three KiwiSDRs: #'s 1 and 2 each have 6 wsprdaemon sockets and #3 has just 2. While #1 will immediately acquire GPS signals when restarted, #2 almost never does - at…
-
I have a bit of follow-up related to the KiwiSDR case fan. It would appear that at least some the noisiness is likely related to insufficient/poor lubrication after all. Having powered down my Kiwi for a week or so due to other work in my shack, I…
-
When you say that the performance of the Mini Whip on the tower is horrible, in what way do you mean that it is horrible? * * * There are a few common traps for those who use an active whip like the Mini Whip, including: - AM Broadcast signal ove…
-
I noticed the DXE devices when they first appeared - and have wondered about them. I did notice that they didn't support POE (hence the claim of galvanic isolation) which means that they would be of little help when it comes to quieting the oft-noi…
-
At the Northern Utah WebSDR, we have 14 "receivers" spread across three 8-channel Kiwis, leaving the first two (full-bandwidth waterfall) channels free for users. This gives us six channels with full waterfalls and four more with the &quo…
-
In listening to that on your Rochester receiver, it doesn't sound like an MW intermod or similar. I poked around at several other Kiwi systems back east - including one near Rochester - but didn't hear it anywhere else. When I first heard it I tho…
-
I have four operating Kiwis scattered about, and at least two of them have somewhat "buzzy" fans - but they are still operating OK. I think that this is more of a mechanical vibration of the fan's rotor than a noisy bearing/bushing, but I…
-
Hi, This thread: http://forum.kiwisdr.com/discussion/1238/any-ideas-am-bcb-overload/p1 contains a lot of useful information about using a KiwiSDR in a real-world environment where it will be subject to both very strong signals (local AM/Mediumwav…
-
I had this exact problem on the Kiwis at the Northern Utah WebSDR system: The "Public IP" that the Kiwi divined did not match the actual public IP of the hostname - this being due to double NATing in the IP network. One thing that was im…
-
That looks to me a bit like a failing switching power supply - but I have also seen this sort of thing with a very lightly-loaded switcher running in some sort of "discontinuous" mode (e.g. it turns on intermittently to maintain a voltage …
-
One thing that I have noticed can cause significant interference below 1 MHz is if the metal case of a KiwiSDR touches anything else - particularly another Kiwi: Clearly the result of a ground loop somewhere as sharing a common antenna ground and/o…
-
When it comes to conducted/induced currents along the length of any cable, a shield connection can be a liability as it, by definition, has no galvanic isolation. The other thing to consider is that the capacitance of the shield to the inner conduc…
-
It would seem the the shield is conducting noise on the "receiver" end to the antenna end in an imbalanced manner, at least partially invalidating the entire point of having a balanced feedline. There is probably a bit of imperfect balanc…
-
Bringing the "naked" GPIO pins from out of the box scares the crap out of me: I would, at least, put series 10k-100k resistors on those leads - both to suppress RF that might be conducted out or in from/to the BBG (which would easily quas…