The other day I was rigging a bag for a job and noticed something odd I wanted to share with you.
In the bag: 788t, 3x Sennie EK100G2 with DC-2 battery eliminators on a Hawkwoods VLR-SQN4S. The 788t was connected to the VLRs fixed cable.
One of the Sennies showed one bar of reception, although all TX were off, and my RF-Explorer one meter away on the table showed an empty spectrum.
I took the RF-Explorer in the bag, and the noise foor was around 9db higher, with a slight sawtooth pattern. I plugged the 788t off the Hawkwood power source and the noisefloor went down. I powered the 788t from the last Hirose connector, but the noise went up again.
I suspected some correlation with the VLRs internal regulators and luckily, I had a Hawkwoods PC-7 with a 2xM Hirose Cable around, that fits with the Twist D-Tap of the Bebob battery. When I connected the 788t directly to the battery, no noise offset was noticable, bingo! Nice side effect: I can now see the batteries current voltage (and therefore if its running low) in the 788t lcd.
With the Bebobs Twist D-Tap, I found a workaround for me. If I'd be stuck with other battery types, I'd try to modify, the VLR and bypass the regulator.