How to keep improving

[Jonnywithacamera]

I have been running the airspy r2 with sdr sharp and the frequency scanner plugin for 225-400mhz with the tram 1410 scanner antenna. I would love tips on how to improve my military monitoring system. I am currently unable to move my antenna outdoors, which is a setback in range. My scan speed is 1.4 seconds. My detect setting is at 60 and the red line (not sure what it does) is around 15 as that is the best spot for sensitivity in my area I could find. IF gain is at 8, mixer gain is at 10, LNA gain is at 12. I am certainly not well versed in the world of radios. I don’t actually know how half of it works, I just got it setup and leave it going so I can know who is nearby my area so I can take photos of the incoming aircraft.

 

[vagrant]

I use a UHFBP 225-400 MHz band pass filter. It is made by Par Electronics. Basically, it reduces signals (RFI) outside of 225-400 MHz. If you have a transmitter/repeater nearby, or one that has a strong signal causing you interference, this filter will suppress those signals while allowing 225-400 MHz signals in.

* Note: I use that band pass filter only with scanners and receivers that I have set to tune in 225-400 MHz. Trying to monitor frequencies outside of that range will be diminished.

I purchased mine years ago for $80. You should expect to pay more than that. There are other 225-400 filters, but this is the one I use.

Scanner Bandpass Filters | PAR Electronics | Filters for the commercial 2 way market, MATV, FM broadcast, laboratory, marine industry, amateur radio, scanner and short wave listening enthusiasts

PAR Electronics Inc. Filters for the commercial 2 way market, MATV, FM broadcast, laboratory, marine industry, amateur radio, scanner and short wave

www.parelectronics.com

 

[gary123]

A bandpass filter like vagrant suggests is good. If you then couple the output of the bandpass filter to a tuned RF preamp with about 20db gain for the same 225-400 you will have the ideal setup. An important note on the preamp you have to get a good commercial quality one. Those cheap broadband preamps are garbage and will undo anything you gain from having the band pass filter.

 

[reconrider8]

A bandpass filter like vagrant suggests is good. If you then couple the output of the bandpass filter to a tuned RF preamp with about 20db gain for the same 225-400 you will have the ideal setup. An important note on the preamp you have to get a good commercial quality one. Those cheap broadband preamps are garbage and will undo anything you gain from having the band pass filter.

What preamp would you recommend running behind the bpf?

 

[prcguy]

What preamp would you recommend running behind the bpf?

I would recommend a MiniCircuits ZX60-P103 for use after a band pass filter. Its got a low noise figure and probably too much gain at about 18-20dB over the 225-400MHz range but you can attenuate the output by 10dB or so. The 1dB compression point and IP3 are also very good for an LNA with low noise figure. I would not use this or most any preamp without a band pass filter.

 

[vagrant]

I do not use more than 10db gain; even less than that is fine.

 

[RichM]

My detect setting is at 60 and the red line (not sure what it does) is around 15 as that is the best spot for sensitivity in my area I could find. IF gain is at 8, mixer gain is at 10, LNA gain is at 12. I am certainly not well versed in the world of radios. I don’t actually know how half of it works, I just got it setup and leave it going so I can know who is nearby my area so I can take photos of the incoming aircraft.

Red horizontal line (Trigger):
When received signal goes above red line, scanning will be stopped and will start listening.

Yellow horizontal (Hysteresis)
After the above has occurred for red line, when a received signal goes below yellow line, the wait
(delay) period starts to countdown, when countdown expires then the scanning will continue.

If signal goes above red line again during the wait (delay) period, the wait (delay) counter will be
reset and the scanner will remain on current frequency. After signal has gone above red line and caused the scanner to pause, the signal can be anywhere
above yellow line to remain paused and not go into wait (delay) state or continue scanning.

Hope this helps. Good luck.