Frequency counter/adjustable close call range device?

[casemods]

As the title states, I'm interested in a device that I can adjust the range on the proximity for detection. I was sad to hear the sds150 will not be addressing this, but also glad that I cant justify the price because of this.

To put it simply, I would like to extend the range of nearby detection that the 436hp has. I always see a band pop up quite a bit more then the others, wherever I am at, but it never captures it! Is there a local city worker talking to another on their radio nearby? I wouldn't know, because I'm not close enough, and the other nearby traffic isn't low enough compared to the nearest signal I want to pop up! 😥

Is it possible to modify a 436hp? Perhaps change the data in the firmware to allow less of variance between nearby signals?

 

[Ubbe]

Get a second hand Whistler scanner that has Spectrum Sweeper. It's sensitivity are between CloseCall and a normal search but its detect time are a bit longer than CloseCall, like 2-3 seconds.

The non SDS scanners from Uniden use a frequency counter IC and as such it needs a single strong signal that stands out from any other signal to make it possible to sample its frequency.

You can help that frequency counter to work better by filtering out all other frequencies by using a narrow bandpass filter, or at least a filter that blocks out the strongest interfering transmitters, like FM/TV broadcast, pager, NOAA and cellular phone systems.

The SDR receiver in SDS scanners cannot detect a CloseCall type of signal in one second using its SDR receiver chip so they probably also use a frequency counter chip. But the specification of CloseCall sensitivity for BCD436 says -70dBm for VHF and -65dBm for UHF and for SDS100 it is -55dBm for VHF and -50dBm for UHF, so 15dB or 30 times worse for a SDS scanner. Normal scanner sensitivity are at -120dBm.

/Ubbe