ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: Kaltman Invisible Waves - RF Explorer  (Read 2847 times)

Gian Luca Cavalliini

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 65
    • Live on Stage
Kaltman Invisible Waves - RF Explorer
« on: February 18, 2018, 02:16:34 PM »

Hi all, long time reading, first time posting...
I'm using both RF Explorer and Kaltman Invisible Waves, big difference in dBm values (tried with same antenna, position, similar RBW. Kaltman is usually reporting lower values (more than ten dB). Has anybody made any comparisons or has ideas about the possible cause?

Gian Luca Cavallini
Logged
LOUDER! - illustrated history of audio and live show evolution. http://www.patreon.com/gianlucacavallini

Henry Cohen

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1220
  • Westchester Co., NY, USA
Re: Kaltman Invisible Waves - RF Explorer
« Reply #1 on: February 18, 2018, 03:09:03 PM »

I'm using both RF Explorer and Kaltman Invisible Waves, big difference in dBm values (tried with same antenna, position, similar RBW. Kaltman is usually reporting lower values (more than ten dB). Has anybody made any comparisons or has ideas about the possible cause?

Neither have precision or calibrated front ends.
Logged
Henry Cohen

CP Communications    www.cpcomms.com
Radio Active Designs   www.radioactiverf.com

Gian Luca Cavalliini

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 65
    • Live on Stage
Re: Kaltman Invisible Waves - RF Explorer
« Reply #2 on: February 18, 2018, 05:38:53 PM »

Neither have precision or calibrated front ends.
Thanx Henry. I'll try to connect directly from some IEM systems (who should have a known output power), hoping to understand which is closer to reality.
BTW, I'm making some test to better understand RF metering on receveirs (different brands and type), I haven't found anything about that in manuals. Maybe I'm missing some existing info source?
Thanx again for this great forum.  :)
GLuca
Logged
LOUDER! - illustrated history of audio and live show evolution. http://www.patreon.com/gianlucacavallini

Ike Zimbel

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1057
  • I'm not a newbie, I just play one on the internet!
    • Zimbel Audio Productions
Re: Kaltman Invisible Waves - RF Explorer
« Reply #3 on: February 18, 2018, 06:34:00 PM »

Hi all, long time reading, first time posting...
I'm using both RF Explorer and Kaltman Invisible Waves, big difference in dBm values (tried with same antenna, position, similar RBW. Kaltman is usually reporting lower values (more than ten dB). Has anybody made any comparisons or has ideas about the possible cause?

Gian Luca Cavallini
Hi, the Kaltman has some pre-amp settings in the front end. I'd have to open the program to explain more fully, and that's not on this computer.
I would be very careful about connecting either unit directly to the output of an IEM system. In any case, with the IEM transmitting through an antenna, both units should be seeing the same level if they are equidistant from the Tx. What is the noise floor that each unit is showing you? If the RF Explorer has a noise floor of say, -85 and the Kaltman has an NF of -95 then you can see that there's a 10db difference in sensitivity.
Logged
~Ike Zimbel~
Wireless frequency coordination specialist and educator.
Manufacturer's Representative (Canada)
Radio Active Designs
Pro Audio equipment repair and upgrades.
~416-720-0887~
ca.linkedin.com/pub/ike-zimbel/48/aa1/266

Diogo Nunes Pereira

  • Full Member
  • ***
  • Offline Offline
  • Posts: 210
  • Barcelona, sometimes...
Re: Kaltman Invisible Waves - RF Explorer
« Reply #4 on: February 21, 2018, 09:46:50 PM »



What is the noise floor that each unit is showing you? If the RF Explorer has a noise floor of say, -85 and the Kaltman has an NF of -95 then you can see that there's a 10db difference in sensitivity.

Isn't the noise floor in RF analysers dependent on RBW (Resolution Bandwidth)? I know the RFExplorer has an RBW value that changes accordingly dependant on span. Don't know if you can change the RBW on the Kaltman leaving the span intact... What are the RBW settings on both units?

I wonder, would different sensitivities still get you the same power metering on a carrier frequency?

I might be hijacking the thread while providing no answers. Sorry for that...

Enviado desde mi XT1032 mediante Tapatalk

Logged
Diogo Nunes Pereira
[email protected]
--------------------------
"I envy not those who own charriots, horses or land. I envy only those who drink water from every fountain." - Popular Song from Portugal

Henry Cohen

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1220
  • Westchester Co., NY, USA
Re: Kaltman Invisible Waves - RF Explorer
« Reply #5 on: February 22, 2018, 07:43:18 AM »

Isn't the noise floor in RF analysers dependent on RBW (Resolution Bandwidth)?

Yes.


Quote
I know the RFExplorer has an RBW value that changes accordingly dependant on span. Don't know if you can change the RBW on the Kaltman leaving the span intact... What are the RBW settings on both units?

The OP did say he used "similar" RBW values, but were they close enough?


Quote
I wonder, would different sensitivities still get you the same power metering on a carrier frequency?

This would also depend on whether the units are set to average or peak detector, but in general, a relatively narrowband carrier strength shown will not be dependent on the RBW, though the occupied channel bandwidth would be.
Logged
Henry Cohen

CP Communications    www.cpcomms.com
Radio Active Designs   www.radioactiverf.com

Gian Luca Cavalliini

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 65
    • Live on Stage
Re: Kaltman Invisible Waves - RF Explorer
« Reply #6 on: February 22, 2018, 06:54:05 PM »

Yes.


The OP did say he used "similar" RBW values, but were they close enough?


This would also depend on whether the units are set to average or peak detector, but in general, a relatively narrowband carrier strength shown will not be dependent on the RBW, though the occupied channel bandwidth would be.

Sorry, quite busy these days, no time for further tests, so here a really fast response.

RBW: controllable in Kaltman and RF Explorer (with Touchstone software). Not available the same precise settings, but very similar and I tried also inverting the smaller value.

Average/peak: I don't have precise info about the way the two systems operate, I suspect this could be one of the cause for average, but it seems strange (to me) for peak level, but maybe I'm missing something...

IKE:
- Kaltman had option "Enable RF preamp (12dB)" active (!)
- RF offset dB was at 0
I made the test with a pair of transmitter (and some noise from local TV...), I'd like to make a test with IEM transmitter (or a generator) just to be more precise (and I know could be VERY useful an attenuator...)

Maybe tomorrow will have time for some further and more precise test...

Thanx again to all of you, I really appreciate the possibility to learn from your great knowledge and experience!

Logged
LOUDER! - illustrated history of audio and live show evolution. http://www.patreon.com/gianlucacavallini

Gian Luca Cavalliini

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 65
    • Live on Stage
Re: Kaltman Invisible Waves - RF Explorer
« Reply #7 on: March 02, 2018, 01:15:48 PM »

Hi there,
problem solved, lot of testing these days and peak (and average) values are now quite similar.
I can't be shure, but the only way to reproduce the 10/15 dB loss was not to completely screw up antenna on SMA connector (it's so near to USB cable, could be first time I've been too delicate...)  :-[

BTW: Kaltman is greatly better about desensing with strong signal. Just press ptt with a little Walkyes (50mw, 2 meter, indoor) and overall signal goes down almost 20 dB on RF Explorer. Nothing similar happens with Invisible Waves... ;)


 
Logged
LOUDER! - illustrated history of audio and live show evolution. http://www.patreon.com/gianlucacavallini

ProSoundWeb Community

Re: Kaltman Invisible Waves - RF Explorer
« Reply #7 on: March 02, 2018, 01:15:48 PM »


Pages: [1]   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.041 seconds with 23 queries.