Joe McElvenney
July 14th 06, 12:39 PM
Hi,
Recently I picked up a NOS GE RF ammeter for a Navy TBS-7 with
the scale calibrated as 0-4A at 70 x 10^6 cycles (their words).
Although I cannot find a manual for it I understand that the
transmitter on this rig put out some 50W from 60 - 80MHz into a 70
ohm feeder.
Now if the load were a purely resistive 70 ohms at 70MHz only
about 0.85A would be indicated making the 4A range seem a bit of
overkill. Although I realise that at some frequencies the opposite
would be the case, 4A does seem a lot. As a result I'm curious
about the way the TBS-7 was matched to the line and wonder if
anyone can point me to a schematic?
Cheers - Joe, G3LLV
Recently I picked up a NOS GE RF ammeter for a Navy TBS-7 with
the scale calibrated as 0-4A at 70 x 10^6 cycles (their words).
Although I cannot find a manual for it I understand that the
transmitter on this rig put out some 50W from 60 - 80MHz into a 70
ohm feeder.
Now if the load were a purely resistive 70 ohms at 70MHz only
about 0.85A would be indicated making the 4A range seem a bit of
overkill. Although I realise that at some frequencies the opposite
would be the case, 4A does seem a lot. As a result I'm curious
about the way the TBS-7 was matched to the line and wonder if
anyone can point me to a schematic?
Cheers - Joe, G3LLV