View Full Version : FM100B+FMBA1=?
08-03-2002, 07:51 PM
I'd like to know how many output I can get with FM25B/FM100B with FMBA1?
the ad says LPA1 can get 1watt max out, but I prefer better filtering, that why I get FMBA1
but when I use this combination, I can get 700m max range (400m max with FM25B/FM100B alone)
then I wander anybody measures the actual output of this combination, I guess it's 300-400mW
08-03-2002, 09:39 PM
What is the fmba1's power supply?
08-03-2002, 10:30 PM
same as FM25B uses
I have 2 working FM25Bs, and I pull one AC adaptor of them to supply power, then I use FM100B instead to connect FMBA1 (because there's too much static caused by excessive RF with FM25B)
08-04-2002, 11:40 AM
Check with a voltage meter to see that you are getting at least 15VDC. It will operate on less, but that is the voltage it was designed to consume. The adapters that Ramsey supplies (AC125) put out around 17VDC+ even though they say 12VDC. Happy Radiating!
08-08-2002, 06:27 PM
I checked it unloaded
I've had good results with Ramsey gear rated for 12 volts using up to 15 volts regulated. The little AC adapter probably does crank out 17 to 18 volts with no load - e.g. just hooking up a volt meter. Depending on the amount of load, the voltage will then sag with an unregulated power supply. For example, I have found that the FM25A and B only use roughly 50 to 80 ma, whereas the LPA1 uses about 250 ma. I use a 0 to 30 volt regulated power supply I built myself, with a ma meter in series and a volt meter in parallel. That way, if anything goes wrong - such as moisture in the coax - I can cut the power, and repair the problem before damaging anything. One time this happened, and the current consumption started to climb quite dramatically! I use a fuse in series with the LPA1 - and it popped thus saving the RF power transistor!
For clarification - the fuse is in series with the positive power supply lead. Don't put a fuse between the RF output and the antenna!
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