Post by thread:[EE]: Design for 40W broadband VHF RF no tune Powe

Russell, That is a design for a 40 Watt VHF RF Power Amplifier for **the FM broadcast band**. In most countries broadcasting by persons not possessing the proper license and authorization to do this is illegal. Don't quite take me at my word? Check out this site where such notices of violation are posted as action progresses against illegal/improper broadcasting (as well as other violations of 'radio law') are posted: http://www.fcc.gov/eb/Public_Notices/ And next time, *please* mention the band/freq range for which the amplifier/device is intended for. Incidently, this particular design has been on the web for quite some time and is linked to from most LPFM and 'pirate broadcaster' web sites. RF Jim {Original Message removed}

I wonder if it can be modified for use on the 6-meter HAM band? Or, perhaps if the transistors can hack it, the 2-meter HAM band? Just a thought.... Dan KC0LUY On Wed, 18 Sep 2002 10:46:45 -0500, Jim wrote: {Quote hidden}>Russell, > >That is a design for a 40 Watt VHF RF Power Amplifier for >**the FM broadcast band**. > >In most countries broadcasting by persons not possessing the >proper license and authorization to do this is illegal. > >Don't quite take me at my word? Check out this site where >such notices of violation are posted as action progresses >against illegal/improper broadcasting (as well as other >violations of 'radio law') are posted: > >http://www.fcc.gov/eb/Public_Notices/ > > >And next time, *please* mention the band/freq range for which >the amplifier/device is intended for. > >Incidently, this particular design has been on the web for >quite some time and is linked to from most LPFM and 'pirate >broadcaster' web sites. > >RF Jim > >{Original Message removed}

Let's look at what this design does: o Designed to amplify the output of an exciter with an output power *significantly* under 1 watt o requires +28 VDC o capable of 20dB gain (ideally .5 W in would yield 50 W out) o contains *no* TR relay Let's look at the "givens" (the usual amateur gear's output power capability, the DC power usually available and other requirements): o Most amateur gear in the one-watt class are FM hand-held portable radios - with a 2 to 5W high power and 1/2 to one watt low power capability. o Most FM *mobile* and even base gear output powers range from 10 W to over 45 W o Any amplifier used with "unit-ized" (integral receiver and transmitter in one package) require a companion amplifier to contain the function of a TR relay to bypass the Power amp during receive o Most mobile gear utilizes +12VDC/+13.8VDC power input o Most passenger vehicles manufactured today are equipped with "12 V" systems Now tet's look at what must be 'modified' for use of this amplifier on the Six Meter amateur band (an octave lower in frequency than the FM broadcast band - at least here in the former 13 colonies!): o Complete redesign of the input matching LC network o Complete redesign of the output matching LC network o Complete redesign of the low-pass output LC filter (you will wind up with an illegal amount of 2nd harmonic coming out of this amplifer if this isn't redesigned!) The bias circuit is probably usable. That's the only upside. With the list of the above "givens", the list of items required to be modofied for use on a band nearly an octave lower and in light of the this design's capabilities - I see a big 'disconnect' in any moves to simply modify it for amateur service on six ... there are better designs with different devices that are better suited for amateur use. RF Jim {Original Message removed}

wow...Jim...cool link to the FCC. Some major fines...20K for violations? wow...guess we can buy a few cruise missles when they collect all those... _________________________________________________________________ Join the world s largest e-mail service with MSN Hotmail. http://www.hotmail.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads