I don't know if this will help, but Charles Classens, RIP recommended the Profi Spion over the Esmog Spion:
"I recommend the Profi Spion over the HF Digitmeter, while he is more
Endotronic made the Profi Spion a bit less sensitive than the Esmog Spion,
because otherwise it makes noise all the time.
No frequencies are determined, but none of the broadband meters do.
And with the Endotronic meters, the signal strength is relative.
Through the big speaker and the electronics, it is superb in showing all the
modulations of the receiving signals. So it is more or less a *hearing aid* for elektrosmog.
The Digitmeter II and the Profi Spion are the only meters on the market, as far as I know, that can measure *hot spots*, when a 6 cm magnetic antenna is mounted.
*Hot Spots* are concentrations of HF and do have the size of a ball.
That way I can measure where people do experience trouble in their head, chest, stomach or legs.
The Impuls Detector is quite good in finding what I call *dirty air*.
Profi Spion has a normal 9V block battery or accu. The one with the power Backup is just for having longer time in use. The difference with the Esmog Spion is, that the profi Spion has this BNC bus, on which other antennas can be mounted. Like the ball antennea, or as the jerries say HF- und NF- Kugelfeldsonde, Breitbandantenne mit BNC- Anschluss"
I have a pdf issue of the May 2006 Milieuziektes.nl featuring a comparison of the HF Digimeter II, VL Spion, Esmog Spion, Profi Spion and Profi Spion 2. I am going to try to attach it here. If it doesn't work, let me know if you want me to email it to you. See here:
Test for the presence of alternating electrical fields (NF)
Test for the presence of modulated electromagnetic radiation (HF)
Measuring ranges: 50Hz - 250kHz or 250kHz - 8GHz
AM demodulation of RF signals
acoustic signal identification base don the sound characteristics
Display of the relative signal strength via LED bar display
Delivery including 3 antennas
I used 2 devices, and one of it was the Esmog spion.
The first device (forgot the name) was a more expensive one, but indeed it only looked for certain frequencies.
I found the Spion could catch things that the other device couldn't, as it was Yes or No, while the Spion made the e-smog BE HEARD in a way.
I could listen to the radio even, on certain parts of my bedroom with the Spion, and changing the little antennas was an easy thing to do.
You may not know what you are listening exactly, but you'll find the places that are much more polluted.
The Spion showed acustically how bad my metallic bed was. It was screaming when I got near it, and it certainly made an impression, while I could not find these frequencies with the other device.
The Spion also showed a lot of noise when my TV was OFF. Only by plugging the cable on the wall the Spion started screaming high frequencies.
There are a few models of the Spion, and I don't remember which model I had in hands.
I can't tell you which model is best, but for me, that was only looking for a better place to sleep, the Spion was good. It could catch more things than the other device, that was a professional device I borrowed for some days.