HOME  |  ARTICLESBAND CONDITIONS  |  EQUIPMENT  |  LINK  | MAIL   |  OPERATIONAL  |  PROJECTS  |  REPAIRS & MODS
       HOME  > PROJECT > 630M TRANSVERTER >
TRANSMITTER CONVERTER FOR 630M BAND

630m band (472kHz-479kHz) Transmitter Converter and common Low Pass Filter. Under development


Under development

The transmit converter consists of four main elements, input attenuator to reduce the RF power from the HF Tranciever down to a manageable level for mixing, ring mixer to mix the 10MHz LO (local Oscillator) with the transceiver RF and produce a linear output within the 630m band (472kHz-479kHz), amplification to raise the output from the ring mixer to a suitable level and finally the low pass filter to reduce unwanted harmonics to a satisfactory level for transmission. 

Fig 1 Schematic of the transmit stage including the input attenuator, mixer, amplification and low pass filter. This circuit is subject to further development.

 

IF Transmitter RF PWR in Watts R1 Details R2 Details
Required Derived
0.5  50 Ohm 5 x 270R 0.5W Paralleled = 54 Ohms 470 Ohm 0.25W
1.0 50 Ohm 5 x 270R 0.5W Paralleled = 54 Ohms 680 Ohm 0.25W
2.0 50 Ohm 11 x 560R 0.5W Paralleled = 51 Ohms 1k Ohm 0.25W
3.0 50 Ohm 11 x 560R 0.5W Paralleled = 51 Ohms 1.8k Ohm 0.25W
5.0 50 Ohm 11 x 560R 1.0W Paralleled = 51 Ohms 2.2k Ohm 0.25W

Table 1 Attenuation network for various power levels. 

 

Component details

TUF-1+ Frequency Mixers Module - TUF-1+
Q1 Transistor - 2N3904
Q2 Transistor - IRF510
C1 Capacitor - 10n 3kV
C2 Capacitor - 10n 50V
C3 Capacitor - 470n 50V
C4 Capacitor - 470n 50V
C5 Capacitor - Electrolytic - 47F 50v
C6 Capacitor - 470n 50V
C7 Capacitor - 10n 3kV
C8 Capacitor - 4n7 3kV
C9 Capacitor - 10n 3kV
FB Ferrite Bead
R1 Resistor Carbon - 560R 0.5W x 11,  See attenuation network table
R2 Resistor Carbon - 1k 0.25W, See attenuation network table
R3 Resistor Carbon - 68R 1W
R4 Resistor Carbon - 6k8 0.25W
R5 Resistor Carbon - 470R 0.5W
R6 Resistor Carbon - 27R 1W
L1 Single layer, close wound air inductor, 5.9uH, 24turns on a 20mm former. See air inductor design
L2 Single layer, close wound air inductor, 5.9uH, 24turns on a 20mm former. See air inductor design

 

Photo 1 Assembled transmit converter.

 

 

 

TOP OF PAGE

Page last revised 18 September, 2017  
 

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.