HOME  |  ARTICLESBAND CONDITIONS  |  EQUIPMENT  |  LINK  | MAIL   |  OPERATIONAL  |  PROJECTS  |  REPAIRS & MODS
       HOME  > PROJECT > 630M TRANSVERTER >
10MHz LOCAL OSCILLATOR

10MHz local oscillator. Under development


The 10MHz local oscillator design is a combination of G3XBM designed local oscillator used for a similar 137kHz transverter and an ARRL Hand Book's local oscillator design for a 160m band transverter. The success of the this 10MHz oscillator will also be the used for a future 137kHz transverter.
 

 Fig 1 Schematic of the 10MHz crystal lock oscillator and buffer stage. This circuit is subject to further development.

Component details

XTAL XTAL 10MHz Fundamental HC49U
Q1 Transistor - 2N3904 TO-92
Q2 Transistor - 2N3904 TO-92
R1 Resistor 100k 0.25W Carbon
R2 Resistor 33k  0.25W Carbon
R3 Resistor 470  0.25W Carbon
R4 Resistor 10k 0.25W Carbon 
R5 Resistor 4k7 0.25W Carbon
R6 Resistor 100 0.25W Carbon
R7 Resistor 100 0.25W Carbon
C1 Capacitor - trimmer 5 - 60pf (35pf)
C2 Capacitor - Ceramic - 100pf 
C3 Capacitor - Ceramic - 100pf 
C4 Capacitor - Ceramic - 33pf 
C5 Capacitor - Ceramic - 100nf
C6 Capacitor - Electrolytic - 47uf 50v
C7 Capacitor - Ceramic - 100nf
L1 FT50-43 Toroidal core Amidon PN# FT-50-43
L2 FT50-43 Toroidal core Amidon PN# FT-50-43

The two RF transformers are wound per Fig 2 & 3 winding details of 10turns of Bifiliar and Trifiliar windings on a  FT50-43 Toroidal cores.

Fig 2 L1 winding details for the matching transformer Fig 3 L2 winding details for the splitter transformer

Photo 1 Assembled L1 matching transformer

Photo 2 Assembled local isolator and buffer circuit.

 

TOP OF PAGE

Page last revised 24 November, 2014  
 

ACTIVITIES | ARTICLES | EQUIPMENT | HOMELINK | MAIL | PROJECTS

Web design by Peter Miles

All content may be used for unlimited distribution with credits.

This site has been designed to cater for 800 x 600 resolution.
Site is best viewed with Internet Explorer 5.5 or Netscape 6 or higher.