rf interference with SIMPLE RF T4 RECEIVER - 315MHZ TOGGLE TYPE

[aes92000]

products being used:
https://www.adafruit.com/products/1097
https://www.adafruit.com/products/1095
http://www.midwestmodelrr.com/product/mie2701/

i am trying to control 4 receivers on channel 'A' at same time with a 3v EL inverter with 9 ft. of EL wire on each. the 4 receivers will be in contained 6'x10' spacing
the inverters are @ 1.428kHz and are creating major interference with key fob when powered on.

i have 2-CR123 3.7V 2000mAH batteries paralleled for receiver @ 7.3V, mid-tapped for inverter @ 3.7v .

i have tried ferrite coils on inverter outputs - both wrapped together in one ring and each separately wrapped with no luck either way.
i wrapped inverter in 4 layers of foil. (may need to put on head also LOL)
i tried to contain inverter and output wires with foil, inside an Altoids tin wrapped with foil. no go

for my design, the inverter needs to be within a few inches of receiver, unfortunately, from limited space.
i need some help trying to limit the interference or options to filter for better reception from key fob.

will changing the antenna to larger and/or longer make a difference?
do i need to design a low pass filter?
is there some type of amplifier circuit for receiver?

any help and/or suggestions are very appreciated (especially since i bought all this crap for a project already.)

[mikerj]

Try using separate supplies for the receivers and EL inverters (i.e. power inverters from their own 3v cell) with the grounds commoned at a single point.  If this improves things then the interference is likely being conducted through the supply lines.

How are you switching the EL inverters from the receiver outputs, e.g. MOSFETs?

[aes92000]

using 3904 with 1K from receiver controlling dpst relay

see if i understand -
separate battery supplies but make common ground between them???
can i omit relay and just use 3904???

including design