View Single Post
  #5   Report Post  
Old January 11th 07, 01:26 AM posted to rec.radio.amateur.homebrew
john jardine john jardine is offline
external usenet poster
 
First recorded activity by RadioBanter: Oct 2006
Posts: 10
Default Electronic inductor bandswitching using ADF4360-8 VCO / PLL


"Joel Kolstad" wrote in message
...
John,

"john jardine" wrote in message
...
Done a bog standard, single transistor Colpitts, that covers 110-220Mhz
using a cheap SMV1255-000 varicap.


What's the power consumption of the VCO? (I'm looking at breaking apart

one
of those ADF4360's into a separate VCO and PLL, since the 4360's use a

*lot*
of power, but apparently most of this is tied up in the VCO since you can
readily get PLLs that are only a milliamp or two such as your LMX2306...)



2ma at 5V.
It's a 2N3819 fet with 1k5 source. Runs about 300mV rms (or, as this is a
radio group +2.57dBm For curiosity, the original fet circuit seemed not
unhappy to be pushed to 500MHz, (on plug in breadboard!).
Noticed the "-7 -8" ADF4360 versions use external Ls. Nice feature (to me)
is that the oscillator is routed internally to drive the DivN counters. At
the moment am using 2 MMC's to give a 1Vrms (apologies, +13dBm) final output
to drive other circuits, ALC and the synth but they burn power like there's
no tomorrow.
john



--
Posted via a free Usenet account from http://www.teranews.com