Need help with a toneburst schematic i'm trying to make one to test my meters 10ms rise time 1db down decay 1.5s to -20db

Try Google. Search for : Bell & Howell 10MS owners manual PDF.

Hi James,

Ground (-12 volt side of the battery) is the entire metallic parts of the car body / frame / chassis. Auto schematics only show non-grounded (+12 volt side of the battery, data and signal) circuits. This is done to reduce clutter and make it easier to read the schematics.

You will find -12V or ground on nearly all metal body / frame / chassis parts of the vehicle. To be sure you are on ground, stretch a wire from the + post of the battery to a test light or the (+) jack or probe of a meter capable of reading at least 12 VDC and touch the the probe connected to the (-) jack to the target grounded panel. If it is ground, you should read 12 volts on the meter - or in the case of the test light - a brightly illuminated lamp. A meter is the preferred device as most people can not tell the difference between a light connected to 12V vs one connected to 10V. The meter assures you of a solidly connected grounded part.

I hope this helps and good luck!

first ck your fuse panel either from 15 to 25 amp bottom of your left leg if the driving position of left side or European on right side,than you might also have to ck that hot wire constint at the back of a radio"IF "the fuse is not the problem,and power wire when Ignition is turn ON...you will need a test light and a volt meters.but do not used a meter to ck. for AMP unless you have a best volt meter could handle with 25 amps and over..ck all your radio connt. wire if its loose wires or radio tips contact with wire connt.,,ck for grown and negative connt. also...some model of a radio aftermarket have a fuse at the back of the radio also,you will need to ck that with test light is it OK or not,if all seem to work fine than Sorry is RADIO need to replace....REMEMBER any radio is over 1db will cause your hearing problem in the future remember thats when you turn on too much of a WATTS

Had an issue with this unit since new. Squelch adjusted too high. Not hearing some signals showing on meter. Solution - find a trim pot labelled "Meter" on the PC board and adjust it like a knobby squelch control. Made a big difference to the number of received stations. Down side is I need to use SQT tight squelch sometimes.

consider a switching relay

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