I recently purchased a Pyramid SVR-200U with the sole purpose of using it as a cross band repeater for the mobile.
I have 900/220/144/and 440 in the mobile with the 440 being an XTS 5000 in an XTVA adapter, so the idea being if I put a DB9 switch on the Pyramid I could then flip the switch and cross band UHF to any of the 3 bands simply ejecting my XTS when I’m ready to go.
There are however a few hurdles that will need to be managed before you can enjoy the SVR on the amateur bands.
The two main issues you’ll find are:
- The software does not allow out of band frequencies to be entered
- The SVR PLL may not lock on a given frequency without going through the tuning procedure.
In this post we’ll go over the process that I used to patch the software to allow out of band frequencies to be entered and in my case it was enough to tune 446.6125Mhz which is likely what I’ll use as my link frequency.
This error is actually vary import as it gives us exactly enough information to patch the software for out of band use.
I prefer to use x64dbg for this purpose but you may use other debuggers if you wish.
Now you’ll want to double click on the first one and you’ll see the following
Scroll up a little bit and you will find the function that makes the decision on whether your frequency is within the band limits or not.
Looking at the above you’ll see an assembly instruction of ‘JE’ which means “jump if condition is met” In other words in our case. Jump if frequency entered is within band limit, if it is it’ll program it but if not it’ll continue onward and show the error message preventing you from going any further.
To fix this we change the ‘JE’ condition to a ‘JMP’ condition which will always jump over the error and trick the software into thinking any frequency you enter is within the band limits.
Next time I hope to go into the process for tuning this radio, however if you’ve no time to wait just grab the service manual online and get to work. The process should be no different than listed.
If you don’t have the tools to do so test the high and low ends of the band (within your authorized frequencies and reasonable within the band plan) and see where it locks.
If the far right light is flashing your PLL is out of lock, try another one.
I’ve uploaded a video tutorial on this topic as well.