The rather massive receiver in this picture is the venerable RAL-7, a WWII era shipboard regenerative TRF receiver. It covers 300 khz to 23 Mhz in nine bands. It is a wonderful CW receiver.
The RAL-7 is a 5 tube TRF design with some neat features that make it very desirable for CW work. It has two stages of tuned pentode RF (6D6) , a pentode electron-coupled detector (6D6), a pentode first audio (6D6), a pentode audio output (41) and an audio derived AGC using a pentode (41).
What makes the RAL-7 so great for CW is its audio filtering; between the detector and first audio tube are a pair of filters. The first is an audio low pass filter with a cutoff at about 1400 hz. The second is a high-Q peaked filter adjustable from about 300 hz to 1400 hz.
There is a fine tuning vernier dial which can be used with the main, un-calibrated logging dial. It has a range of about 2 khz. Audio output is 600 ohms at about 1/2 watt. I usually use a 600 ohm LS 166 ruggedized jeep speaker. Power supply requirements are 90 and 180 VDC nominal, at about 40 ma. It will run just fine on a single 90 VDC supply. Also a 6.3 VAC filament supply is required.
Sitting on top and to the left is the ARC-5 command set- note the variable capacitor sitting on top- I need this so that I can load my 67' inverted L antenna with this transmitter. This particular unit covers 3.0 to 4.0 Mhz. It is a classic MOPA design, and uses a pair of 1625s in the final.
To the right of the command set is a BC221 frequency meter. I use this in conjunction with the RAL-7 to obtain dial calibration points- the RAL-7 has only an uncalibrated 0-100 logging scale.
Below all the gear are the power supplies- the black box with the big transformer is the power supply for the ARC-5 transmitter ( as well as other projects ). The skinny looking box is a power supply I picked up at the local electronics surplus store, suitably modified for the RAL-7's modest requirements.