Greetings,


Anyone one have an idea where to get basic info on low power fm exciter/transmitter construction and setup. Neighbor kids run (ran?) a pirate fm (90.5MHz) station with old, unmarked, kit transmitter (20 watt). Seeking more 'watts', someone turned up up bias control in exciter and burned out transistor. I need to find info on how to set the bias, and there isn't any easy way to monitor collector current. My experience and test equipment is limited to HF am/ssb(<30MHz) and this is a new animal. Any technical help or directions to any resources would be appreciated. I'm their only hope to get 'airborn' again. Thanks for any help.

Just take a huge surf on internet and seek for a suplyer in the near area. use www.gogle.com


and seek for example for broadcast equipment. try al kid of divirand freases.


grtz Dave H

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Replying to:

Greetings,


Anyone one have an idea where to get basic info on low power fm exciter/transmitter construction and setup. Neighbor kids run (ran?) a pirate fm (90.5MHz) station with old, unmarked, kit transmitter (20 watt). Seeking more 'watts', someone turned up up bias control in exciter and burned out transistor. I need to find info on how to set the bias, and there isn't any easy way to monitor collector current. My experience and test equipment is limited to HF am/ssb(<30MHz) and this is a new animal. Any technical help or directions to any resources would be appreciated. I'm their only hope to get 'airborn' again. Thanks for any help.

Give us more infos for the circuit of the Tx unit.Usually FM transmitter amplifier stages are at class C type and don't have bias at base (speaking for NPN BJTs).Also it will be good to know the transistor type, and /or the kit maker to give you infos on the subject. Meantime you don't have to measure C current. An easy way to check if the final is working is, to disconnect it from the power supply (unsolder the collectors RFChoke) and monitor the changes of the total current the device draws.


Regards


Sotris Pdmtr




ASPiSYS Ltd.


http://www.aspisys.com


P.O.Box 14386


Athens 11510


GREECE


Tel : +301 0771 9544


Fax : +301 0771 4983


FM & TV PLL transmitters at :http://www.aspisys.com/products.htm

--- --- --- --- --- --- --- --- ---

Replying to:

Just take a huge surf on internet and seek for a suplyer in the near area. use www.gogle.com


and seek for example for broadcast equipment. try al kid of divirand freases.


grtz Dave H

--- --- --- --- --- --- --- --- ---

Replying to:

Greetings,


Anyone one have an idea where to get basic info on low power fm exciter/transmitter construction and setup. Neighbor kids run (ran?) a pirate fm (90.5MHz) station with old, unmarked, kit transmitter (20 watt). Seeking more 'watts', someone turned up up bias control in exciter and burned out transistor. I need to find info on how to set the bias, and there isn't any easy way to monitor collector current. My experience and test equipment is limited to HF am/ssb(<30MHz) and this is a new animal. Any technical help or directions to any resources would be appreciated. I'm their only hope to get 'airborn' again. Thanks for any help.

Webpage www.geocities.com/pdmtr/fm