Total posts : 45366
One of the things I did with my Ramsey FM100 (the older model not the FM100B) was to add a cooling fan to the chassis just above the power transformer. I drilled a series of holes for air flow in the metal cabinet and added a cooling fan commonly used as computer heat sink cooling fan.
My FM100 was NOT the export kit so it did not come with the 1 watt module. I used the telescopic antenna that came with the kit.
I just wanted to add to the conversation here that I added that cooling fan, because I witnessed an increase of heat on the cabinet top and felt that heat could cause premature failure of the filtering electrolytic capacitors or a possible chip failure.
I noticed the mention of the FM100B with the 1 watt mod causing heat issues, but I wanted to stress that I noticed heat issues with the kit being USA ‘stock’ legal.
The interesting part of the Ramsey FM100 kit is there is NO certification number on the chassis. I also did not see any mention of such in the kit building manual included with the kit. So, I have ask, are they really legal for use in the USA? I see a lot of talk by many that those FM100 and FM100B’s are operating above part 15 authorization. I used an analog Diamond SX-200 meter on mine and the meter in the zero to 5 watts range barely ever budged past zero, you really had to watch that needle for any movement and that was using the external antenna output and a 50 watt dummy load.
I no longer have my FM100, I sold it to a local ham operator about 2 1/2 weeks ago, but I figured I’d share with the rest of you what mod’s I did to mine.
Oh, ONE LAST thought. One thing I noticed about my kit. It was built properly, but the BA1404 chip was wired wrong in my kit for the L-R audio inputs. The left audio amplifier was wired to the BA1404 right input and the right amplifier was wired to the BA1404 left input. So basically, the channels were REVERSED at the transmitter output and was the case on an FM stereo receiver.
I even contacted Ramsey about it and they said the makers of that kit were no longer with Ramsey.
I had to cut the traces to the BA1404 chip Left Channel and Right channel inputs and jumper over using jumper wires to correct the problem and restore the channels to their prospective zones.
I have not seen anything on the web about that, so I must be the ONLY one who caught that circuit board error.