FM100B Noise?

[ringbr]

Hi. A few days ago, I got done building the FM100B tx. I'm pretty satisfied with it, but without modulating any audio, or low audio levels, I hear some pretty noticeable hiss, louder than my FM25A tx. This is not just through one rx, but through any rx from a portable radio to a car radio. Is this normal, or could there be a problem somewhere? It's ok if it's normal, but if it isn't, then I would like to find some may to "improve" it.

Thanks

[jay]

How high do you have the power set. If the power is real low, the receiver might not be getting enough signal for a full quieting stereo carrier.

[ringbr]

The power output is set to full power assuming about 25mw. I did slightly turn down the power to see if the receivers were overloaded, wasn't that. I switched to an external antenna on the roof (with the FMLP1 filter inline) a little better, but still has the slight hiss.

[mingkee]

do you turn your receiver volume all the way up?
I have 2 FM100B, I can hear a little bit hiss when I turn my walkman volume all the way up
since FM100B employs fully-regulated power supply, the hum/static is almost inaudible
if you hear a lot of hiss, even under normal volume, it's time to check your grounding, and try different receiver to find out (walkman is the best bet)

[ringbr]

Yes, with any receiver (big home stereo system or car, to a walkman) with the volume all the way up, some hiss is present.

[mingkee]

don't worry
it's normal
because mine is
since the SN is around 40dB, a little bit hiss is heard when you turn your receiver volume all the way up

[jay]

That would have been my next question, regarding the volume. I think Matt's answer is on target