After successfully building my 0V1 receiver with an ECC81 tube, I searched for a suitable template for an even better device. Technik-Versand company from Bremen, had published a number of amateur radio kits under the label "Teva", including the Audion receiver presented here. It seemed very suitable for reproduction. In addition, the device was expressly praised by an older OM: He had once possessed such a device. So I set out to build a device in accordance with this circuit template, but without using the kit. I soon found the parts I needed by disassembling old broadcast receivers.
The two-stage audio section with the right-hand ECC81 offered sufficient gain reserves, also for the loudspeaker reception of weaker stations. The left ECC81 was used in a cascode audion formation. The regeneration feedback or respectively the oscillation generation came about in the manner of an ECO oscillator. The feedback adjustment with DC via a bias shift of the system operated in grounded grid circuit resulted in only minor frequency alterations. This receiver proved to be superior to a regenerative circuit using a pentode with adjustable screen grid voltage in my experiments. The regeneration onset was pleasantly soft and the sensitivity was very good. Due to the three antenna connections, the coupling could always be well adapted to the reception situation and to the existing antenna. The upper antenna socket was better for longer antennas, the lowers for shorter ones. The smaller detector level with slacker coupling resulted in less distortion by synchronization in the SSB reception and could be compensated well by higher audio gain, reachable with the two AF stages. To simplify the replica, here the winding data for the plug-in coils for receiving the classic SW amateur bands (coil diameter each about 30mm):
80m band: abt. 29 turns enamelled copper wire 0,3mm, tapping at 5 turns, parallel C = 33pF
40m band: abt. 11 turns enamelled copper wire 0,7mm, tapping at 3 turns, parallel C = 82pF
20m band: abt. 5 turns enamelled copper wire 0,7mm, tapping at 2 turns, parallel C = 27pF
15m band: abt. 3,5 turns enamelled copper wire 0,7mm, tapping at 1 turn, parallel C = 68pF
10m band: abt. 2,5 turns enamelled copper wire 0,7mm, tapping at 1 turn, parallel C = 82pF
Read, listen and watch!
Sanaphantastron is a somewhat unusual music project outside of mainstream.
On this website you can get lots of interesting information about it and hear music from Sanaphantastron. We hope you enjoy reading and listening!
here you can hear different music from Sanaphantastron. It is selected in an infinite loop by random generator. So you can run this link like an internet radio on the side.
what nobody needs...
...and hardly anyone likes to hear. The main thing is to make it makes fun!
Sanaphantastron is a mixture of a traditional music combo of different orientations and an experimental music project.