G8JNJ
About
- Username
- G8JNJ
- Joined
- Visits
- 3,448
- Last Active
- Roles
- Member
- Points
- 400
- Location
- South West UK
- Callsign
- G8JNJ
- Additional information
- https://g8jnj.net/web-sdrs
Reactions
Comments
-
Hi Jimmy, The PA0RDT amplifier has a very high input impedance, because it is designed to interface with the plate / whip element directly. It acts more like an electronic "impedance convertor" to 50 ohms, than an actual amplifier with gai…
-
Yeh, that catches me out too, more often that it should. You need to clear your browser cookies in order to get the "new user" experience. Some browsers don't like letting go of all the stored settings, Chrome in particular sometimes seem …
-
Most folks set it according to their location, and the default value may not always be suitable. I normally choose a strong local broadcast station, with the appropriate mode and bandwidth so that new users at least hear something when they first c…
-
"Now to work on a better antenna" Ha, good luck, that's where the fun starts. As soon as you can 'see' a continuous swathe of spectrum from 0 to 30MHz with a KiWi, you begin to realise just how much noise and interference is present, that …
-
If you have just got your K2, it may not so far have updated to the latest version. Have you tried doing this manually via the admin interface ? Almost any image size about 350 pixels tall, can be made to fit, but you may have to try rescaling it a …
-
Sorry, my wording was unclear. I meant that the attenuator setting would be only accessible via the admin interface. If it is not made available to a user, it could be confusing if the control is still present, even if greyed out. But I now better u…
-
Hi John, My personal view is that I think the attenuation slider setting should be an admin only adjustment, especially as it has a 30dB range. I also think it can be confusing when users can't adjust it (as per the initial post), and it currently t…
-
As the weather was a bit better today, I decided to try adding a PGA103 preamp to the Apex clone. The signal (and noise) levels are now pretty much the same as all the other active antennas I have connected to my home KiWi. https://forum.kiwisdr.co…
-
Hi Jimmy, I have now placed the improved Apex clone outside and connected it up to my home KiWi, so try it again and see what you think. Generally speaking, the performance in terms of absolute signal levels is about 10dB lower than I'm obtaining fr…
-
Hi Jimmy, Thanks for those new links, most useful. In one of the Japanese links, someone has tried to measure the impedance match, but they have just connected the antenna directly to an antenna analyser, without the coax cable bing present to provi…
-
Hi Jimmy, I was intrigued by your passive whip antenna, the ApexRadio 303WA-2. I did a bit of research online and managed to find some notes regarding its construction. It is basically a 1.7m long whip, connected to a 64:1 ratio broadband Unun trans…
-
Thanks for the SNR update, that will be very useful for testing. Regards, Martin
-
Hi Ben, Thanks for this, but for some reason I don't seem to have received your PM. If you have a look at the recent antenna thread, you can see a photo of some of my antennas. https://forum.kiwisdr.com/index.php?p=/discussion/3106/antenna-recommen…
-
Whatever you use, it is likely to have to be a bit of a compromise. Active monopole / E-Probe - Very small and easy to hide, good performance from VLF to 30MHz + Omni-directional. Being an unbalanced high impedance antenna, it is very prone to noise…
-
The pins on http://rx.linkfanel.net/ move around when you refresh the browser. Apart from randomisation, I think it is to ensure that all the pins are at least visible at some point in time, and not masked by others. https://forum.kiwisdr.com/uploa…
-
Agreed, the latest enhancements make it so much easier to find KiWi's with decent reception of the target transmitter. Thanks again John for all of your hard work. Regards, Martin
-
I just checked with my KiWi V1 & V2, which are both fed from the same external GPS antenna using an active splitter. The performance is pretty much identical, but the system noise figure and sensitivity in this case is being defined by the GPS a…
-
Ah, that's why I didn't have any problems, as I've yet to bite the bullet and upgrade to Debian 11. I think I wait a while longer if problems like this occur, especially if something this basic is missing. However, I'm pleased that you managed to re…
-
Hi Nate, I don't know why you are experiencing this problem. Background autorun doesn't have any effect on the image being displayed. Could it be a problem with your image editor od choice appending the file with something that the KiWi doesn't lik…
-
Hi John, Great, thank you. JSON is fine. My thinking is that it may be possible to use this to drive some form of external AGC, or at least be able to post when the majority of ADC overloads occur. Regards, Martin
-
Hi John, Could that also return the existing count before it was reset ? That would save having to view different sets of stats, and be handy for a quick automation process. Regards, Martin
-
I'm assuming the problem is due to direct sunlight on the black GPS puck, causing it to overheat. Can you shade the antenna in some way, with a material that will not block the GPS signals ? Regards, Martin
-
Hi Bob, Your guy is actually a bit thinner than I expected. The cores I suggested will accept 1" diameter, and they split in half and clip back together. So you can easily clip one over a guy, and let it rest against a turnbuckle or whatever, t…
-
Hi Bob, OK all good. I was thinking that you could perhaps make a coupler, to fit over the steel guy rope. Something like a big Fair-Rite split ferrite core. https://fair-rite.com/product/round-cable-snap-its-431177081/ https://fair-rite.com/product…
-
Hi John, Thanks for the explanations. I'll try to remember that I have already mentioned these, to save troubling you with them again. Regards, Martin
-
Hi John, Thanks for the TDoA waterfall enhancement, it is a very useful enhancement. There are a few slight issues I have noticed during use, but they may have been present for some time. ----- When there are several KiWi's on the same site, it is q…
-
Hi Glenn, The type I referred to are the low'ish' cost units available for the amateur market, and these tend to use narrowband tuned circuits or R/C networks in order to provide the required variable phase shift networks. But I do agree with you, i…
-
Hi Ben, Yes, I'd like to have a look at that if possible. I've currently got problems with my VHF/UHF OpenWebRX sdr's at the Wessex site. The signal levels are fading up and down at random intervals, and I'm trying to figure out the likely cause. I …
-
Hi John, That's a good idea for the TDoA selection and would certainly help. I wonder if it would be possible to perform some other quick comparison to validate if the selected KiWi's are actually receiving the target signal. I often find when I per…
-
Hi Ben, It's an interesting idea. I wonder if something like CatSync could be modified to do something like this. Maybe contact Oscar, DJ0MY ? Regards, Martin