RFX400 daughterboard@200MHz

GNU Radio
1

Hi,

I am about to modify a RFX400 daughterboard to operate around 200MHz by
changing inductors as explained in the wiki.

Has anyone tried this successfully before for frequencies below 300MHz ?
I am doubtful about the final TX amplifier of the board (RF3315 from
RFMD) that specify a minimum frequency of 300MHz. Can it be pushed down
to 200MHz ?
If not, does someone know a replacement amplifier circuit ?

Thank you.

Mc
PS: Any news on the WBX0510 daughtboard (50MHz-1GHz) release plan ?

2

Hi Mathias,

Yes, I have. However to get it to really work at ~150MHz, I had to
change the VCO with an ADF4360-8. After the tricky job of removing the
original VCO, you also have to modify the db_flexrf files such that it
configures the VCO dividers correctly. We did finally get it
transmitting in the 145MHz ham band.

If there is additional interest in this band, I would love get a patch
summited with these code changes, particularly if we assigned this set
of mods / board configuration with it’s own ID such that both the
standard flex400 and this modified flex200? would both work.

I don’t have a list of the final mods handy, but I think there where
various other filters at least that needed to be changed out.

Glenn

3

Mathias C. wrote:

Hi,

I am about to modify a RFX400 daughterboard to operate around 200MHz by
changing inductors as explained in the wiki.

Has anyone tried this successfully before for frequencies below 300MHz ?
I am doubtful about the final TX amplifier of the board (RF3315 from
RFMD) that specify a minimum frequency of 300MHz. Can it be pushed down
to 200MHz ?
If not, does someone know a replacement amplifier circuit ?

Thank you.

Mc
PS: Any news on the WBX0510 daughtboard (50MHz-1GHz) release plan ?

i successfully modded several cards for 200-300 mHz range, i havent
tried below 200 mHz though