Expanding/Changing Frequency Monitoring - I'm an idiot.

Psychlonic

So here's my problem. I have a radio which monitors the 148-174 MHz range. I would like it to also monitor the 406-512 MHz range.

I'll be honest - I don't know dick about modifying radios but I am careful with changing electronic components and I can follow instructions. The radio in question is not a cheap one, it's a BK GPH5102X. I realize that I'm tampering with a >$1000 radio and telling me if I have to ask I shouldn't mess with it doesn't help.

How is frequency monitored? Resistors that regulate the bands? If it's swapping out resistors I'm confident I can manage. If anyone has anything on BK radios specifically, that would help immensely.

Anything else a newbie should familiarize himself with? If I don't feel I can do it, rest assured I'm not going to fuck with it. With good instructions though I feel I can.

Daktologist

Psychlonic wrote: »

So here's my problem. I have a radio which monitors the 148-174 MHz range. I would like it to also monitor the 406-512 MHz range.

I'll be honest - I don't know dick about modifying radios but I am careful with changing electronic components and I can follow instructions. The radio in question is not a cheap one, it's a BK GPH5102X. I realize that I'm tampering with a >$1000 radio and telling me if I have to ask I shouldn't mess with it doesn't help.

How is frequency monitored? Resistors that regulate the bands? If it's swapping out resistors I'm confident I can manage. If anyone has anything on BK radios specifically, that would help immensely.

Anything else a newbie should familiarize himself with? If I don't feel I can do it, rest assured I'm not going to fuck with it. With good instructions though I feel I can.

generally a crystal oscillator is used to provide tuning into a particular frequency range as far as i know, im not really into radio mods or more haven't tried it yet would a way to describe it google doesnt seem to have too much info on mods for that particular model either. unfortunately i dont know of anyone here who has a good knowledge of modifying radios that i know of , hopefully over time we will find more members with knowledge in that area. i imagine a mod like that would be similar to the band expanders that allow japanese car radios to work on the normal 87.5 to 108.0 MHz FM band except allowing you to receive the the 406-512 MHz range on the 148-174 MHz band. last time i looked in a band expander it had a crystal oscillator that shifted the input frequency to that of the receiving frequency of the radio so designing a similar circuit to that could be your best bet, unfortunately with some reduction in gain

Psychlonic

Well thanks for the help, maybe I can tear apart some actual police scanners just to look at their circuits to see how they do it or maybe even find a way to get multiple ranges through patents on the USPTO website. I checked out some of the links in your topic below regarding mods, but maybe I just don't know what the fuck I'm doing since I couldn't seem to gain anything useful for my particular project out of them. I'll look into the expander idea as well.

Anyways, it might be awhile before I get on this, but if and when I do I'll let you know how it goes for anyone else who might want to give it a shot.

Daktologist

I once hooked a car radio FM expander to my scanner to get FM radio on the Japanese FM band and it worked, I imagine that you could make changes to it so other frequency's fall into the range of your radio. sorry I couldn't be of more assistance but I would try and find a guide to modifying band expanders as it doesn't require changes to the internal circuitry in the radio and saves damaging an expensive radio