Hi Bodger, I'd like to know that too.
Antenna building and modelling using software and testing them and analysing them has been my main radio passion for years, because I live in the sticks I can hang them from trees, they are made from aluminium welding wire.
I've done a bit with the SDRPlay RSP2 on HF and also multi-coaxial-collinear VHF-UHF verticals using an inexpensive RF noise source and a MiniCircuits bi-directional coupler from eBay
The coupler is a MiniCircuits ZFDC-10-5-S+ which is good for 1MHz to 2GHz and the noise source is one of these
https://www.ebay.com.au/itm/Noise-Sourc ... Sw4PxaBoVR
I can't find the original article online that started me off but if you search you'll find a variety of articles that deal with sweeping filters, antennas, etc all using the same principle.
There's a post on this forum from someYguy that might get you interested.
viewtopic.php?t=1562
Pros:
Really great for sweeping 10MHz blocks of spectrum using an SDRPlay device
Terrific visualisation of what's happening
Versatile for a range of things, eg sweeping common mode chokes, sweeping antenna tuners to see depth of notch or bandwidth
Cons:
Dynamic range measuring ability is limited by the return loss specs of the coupler, eg.
https://www.minicircuits.com/WebStore/d ... -10-5-S%2B
Absolute values are not easily obtainable because of the lack of ideal "flatness" of a cheap noise source and the coupler.
With the things I do, the relative values are what counts.
Here's a pic of the setup used to evaluate the notch obtainable by using an antenna tuner as a shunt to ground.
viewtopic.php?f=8&t=127&p=9283&hilit=an ... uner#p9283
Using an RSP device as test gear has great potential, especially given it's += a dB or two flat range to 2GHZ.
All we need is a nice tracking generator and more dedicated software
Here are a couple of screen shots of one of the 160m loops, SDR-Console software was easiest to adjust for spectrum range and colour.

- HFloop1-1-8-small.png (149.43 KiB) Viewed 20084 times

- HFloop2-11-19-small.png (162.79 KiB) Viewed 20084 times
Links to originals:
http://www.vk7jj.com/public/HFloop1-1-8.png
http://www.vk7jj.com/public/HFloop2-11-19.png
With the accessibility of SDRPlay hardware and the range of software and it's uses, we can confirm on the bench that the sky is the limit
Cheers,
Phil