G8JNJ

Yeh, I realised you were joking.

If you live in that part of the world, then I'm surprised you can hear anything other than radars :-(

The Wave radar you mentioned is very strong in Europe, which is why I thought it must be located over this direction, but I could be wrong.

Wave radars do occupy more than 50kHZ, so the SigID Wiki is incorrect.

The list of US Wave Radars can be found here (warning, it takes a long time to load) This also states their sweeprate (typically 1, 2 & 4 seconds) and bandwidth (some are 100, 600, 1000kHz)

https://hfrnet.ucsd.edu/sitediag/stationList.php

Another list containing European projects (also slow to load) click on the "download metadata" option to get a list.

https://www.hfrnode.eu/map/

If anyone does find a list for Asia, Australia etc. I'd be keen to see it.

Regards,

Martin

Sorry to dissapoint.

It's a Wave radar, but it must be a new one, as it's not on my list of European or North American ones.

Most likely during a contest or similar.

When some of the big contests are running, like CQ Worldwide, the amateur bands are usually packed.

Most contests tend to held during the weekend.

Regards,

Martin

There was an extensive thread regarding the 393WA

https://forum.kiwisdr.com/index.php?p=/discussion/comment/17852#Comment_17852

"I would like to invest in the W6LVP"

Also pretty average IMHO, I'd go for LZ1AQ, used Wellbrook or Cross Country Wireless.

Check out the Loopantennas IO group, ready built PCB's on offer at decent prices.

Regards,

Martin

Hi John,

Not a big deal, but it may be related to the mouse behaviour.

I notice that sometimes when I click on the waterfall, the KiWi doesn't tune to that frequency, but it remains on an existing frequency. A second click is then required before it tunes correctly.

I have only noticed this over the past month or so, but it may have been like this for a while.

Regards,

Martin

The gain control on the bias tee is a passive one, so it's probably best to set that for minimum attenuation and maximum signal levels anyway.

Then adjust the gain control on the loop amplifier board.

There is no point adding more gain than necessary in the loop amplifier, only to counteract it by applying attenuation later in the signal chain.

Ideally, you should aim for approximately 6dB increase in the KiWi noise floor at frequencies around 20 to 30MHz, when the antenna is powered.

Any more than this, and you will not improve the Signal To Noise Ratio, but you will be eating away at the receiver's dynamic range, and making it more prone to overload on strong signals.

A 6dB increase in noise floor, when the antenna is connected, is the "sweet spot" to aim for.

Regards,

Martin

This is a typical data sheet for the type of ceramic patch used in the small GPS puck.

https://datasheets.kyocera-avx.com/ethertronics/AVX-E_1001039.pdf

Note the 70x70mm PCB ground plane used in the measurement test setup.

The 30x30 PCB inside the puck is really just a bit too small, and the polar diagram and off-axis noise rejection is improved by having a larger ground plane below it.

Many of the external GPS antennas are basically just the guts of a puck, mounted on a larger ground plane, and inclosed in a waterproof housing.

Regards,

Martin

I watched one of Techmind's video's relating to the End feed antenna.

https://youtu.be/VYt3-jkBfaQ?feature=shared

Some things of note.

He is on the edge of rural farmland, so the noise floor will be lower than if he was in the middle of at typical UK housing estate, it is also likely that his utility services will be buried rather than being carried by overhead wires, which will further improve the noise floor.

He has installed the antenna in the best way possible, with the feed point located way from the property, and he has also installed a choking balun and separate RF ground, although this could be further improved. Ideally, he should also have incorporated some form of galvanic isolation, in order to reduce the risk of ground loops, or possible issues with UK wiring regulations and mains safety.

Regards,

Martin

I wouldn't trust a Chinese made torque wrench.

It's unlikely that the KiWi will be repeatedly connected and disconnected as much as some other equipment.

Slightly past hand tight is fine, and don't use a big adjustable wrench.

Regards,

Martin