Have just completed a 40mtr (7Mhz) superhet transceiver, the design is based on commonly found PN2222 transistors. The radio features:RF Gain Control
IF Filter bandwidth Adjustment
RIT
AF Gain Control
Picture Showing the 2N2-40+ Transceiver
(On top is a homebrew Stockton (SWR) Power meter)
The receiver has excellent sensitivity with narrow bandpass filters in the front end preceding a "Norton" designed low noise RF amplifier then a double balanced mixer using 1N4148's which mixes the input signal (7Mhz) with a 2Mhz from the VFO (Variable Frequency oscillator). The mixed product is then sent on to a 3 Pole variable bandwidth crystal stage of 4.915MHz.
The TX output power is 2 Watts QRP, using three paralleled 2n2222 transistors.I have only given a brief flavour of the radio. For more information with detailed specifications see the designers web page of Jim Kortge, K8IQY.
On the web page you will also find useful information on Manhattan construction techniques and useful homebrew test instrumentation.
Jim has given me valuable support in sorting out problems that may be encountered in construction and was certainly an inspiration to me in getting this Project working. There is also a Yahoo 2n2-40 website for the 2n2-XXXX versions where a wealth of information can be sourced for fault finding and help on building the radio.
