From Spiros, SV8CS, “A rare GRC 9 made in Germany by Telefunken!!. Now listening on 40m with a piece of two meters wire.”
Thanks Spiros.
From Bruce, W1UJR….
The transmitter was originally roughly based on the MOP in the September 1928 QST and the modulator in the April 1929 QST, with numerous modifications for reasons of convenience or part availability. The appearance was based on the 1928 Aero Radiophone transmitter.
After it was completed, the following changes were made to remediate shortcomings in the original device:
1. Relocation of the neutralizing capacitor to prevent hand capacity effects.
2. Switching the power to the modulator by breaking the cathode lead instead of the plate lead to prevent occasional arching.
3. Increase in the number of turns in the amplifier and antenna coils to allow greater plate efficiency.
4. Cutting an "X" across the amplifier tube socket after it failed due to high RF voltages.
5. Replacement of the regular tuning dials with National Type-A Velvet Verniers for easier tuning.
6. Addition of optional crystal control to allow for easier operation and better performance.
7. Replacement of the antenna ammeter with an oscillator plate current meter as it was deemed more important.
8. Installation of a resistor in series with the power amplifier to reduce plate current during overload conditions.
Thank you, Bruce!
This unit and the tapes for it came from a K9DBR SK, from Janesville WI.
Just needed to clean the lamp assembly and it worked!
Gary - KB9VGD
R1155 Receiver in Action!
Here's a real treat! Our friend, Nik Leitz, sent us this video of his working R1155 receiver. The R1155 was a British communications receiver, commonly used in aircraft along with its associated T1154 transmitter. It was used extensively by the Royal Air Force during World War II, mainly in larger aircraft such as the Avro Lancaster, Handley Page Halifax, Vickers Wellington and Short Sunderland.
Realistic, DX-302, shortwave
Rod, VK2FCAA, sent us this video of his DX-302 on shortwave.
Rod, VK2FCAA, sent us this video of his WWII, Morse code signal light.
