G8JNJ

I'm quite pleased with this one, especially as it's an HF signal and there are not that many suitably placed KiWi's.

It's a Russian CIS-12 signal on 11175KHz.



Regards,

Martin - G8JNJ

I'm quite pleased with this one, especially as it's an HF signal and there are not that many suitably placed KiWi's.

It's a Russian CIS-12 signal on 11175KHz.



Regards,

Martin - G8JNJ

Hi John,

Excellent and very timely :-)

There is currently a problem with a military FSK signal in the 40m amateur band that folks have been trying to ID. I ran a TDoA on it this morning and was able to narrow down the likely transmitter site fairly accurately (given the number of KiWi's currently listed.

So a big thanks to all concerned especially John, Christoph, linkz and others who have managed to make this work.

I don't think I'm overstating it when I say that this is likely to be a real game changer, especially when trying to ID unknown or interfering signals and makes what would previously have been only within the capability of national regulators or the military available to everyone.

This is truly ground breaking.

Regards,

Martin - G8JNJ

Hi Ron,

Reducing the loop inductance (for a given size) is something worth trying if you want to improve the performance still further on the HF bands (>10MHz).

This is less critical when you are using a loop amplifier with a fairly high input impedance, but in the LZ1AQ design it is only in the region of a few ohms (which is great for the LF bands), so loop inductance becomes a critical factor as you go up in frequency.

You can either make the loop a lot 'fatter' to reduce the inductance, connect several same size loops in parallel (but spaced by a few inches), or cross-connect four or more independent loops together.

Chavdar has good notes on this subject on his website.

http://active-antenna.eu/tech-docs/3_ActiveAA_Antena_11.pdf

Regards,

Martin - G8JNJ

Hi Ron,