The FRG-7 is a good radio out of the box, but it is even better after two
mods.
The first one is bypassing the signal chain that has the MW attenuator.
Simple rerouting of the input signal to the unused contact of the
preselector switch that is associated with the MW range does the trick.
After that, you can use either the 50 Ohm antenna input or the high Z jack.
The MW antenna jack is no longer used.
The second mod is to bump up the gain in the 455kHz I.F. strip a bit. Yaesu
uses a partially bypassed common emtiier configuration for the two 455kHz
I.F. amplifiers. This consists of using two series resistors for the emitter
return instead of only a single resistor. The bottom (cold) resistor is the
only one that is bypassed. The reason for this is to introduce some negative
feedback for stability. Since this device is running at such low gain in the
first place, instability isn't really a factor. They may have run into gain
variations from batch to batch, so this was one way of providing consistant
gain.
If you want extra gain, simply connect the bypass capacitor from emitter to
ground. This puts the emitter at AC ground...........the gain equation now
changes. Instead of the gain being Rc / Re, is now becomes Rc / Re'.
A simple way to calculate Re' is by using the formula [25mV / Ie]. This is
usually 25 Ohms or less, depending on the emitter current that the device is
running at. A good way to get some extra gain without disturbing the DC
operating point of the device. Thermal stability is unaffected.
Gain of the receiver is similar to an Icom R-75 or a Drake R7 after this
mod, and MW sensitivity is as good as the best out there.

Pete