Solidstating DDR sw-receiver EKB

[PA0CHS]

DDR receiver EKB

Many years ago I started a project of "solid-stating" DDR manportable sw-receiver EKB. This receiver is a double super with a first IF of 900 KHz and the second IF is 32 kHz. Frequency range is from 1,5 to 22 MHz.
The internal HT-inverter delivers 60 volt, LT is 1,2 volts via a 7,2 and 1,2 volts NICAD battery.
The EKB is a "hybrid" receiver: the HF and IF-stages are using penciltubes DF669 and one miniature tube DF97.
The AF-stage uses germanium transistors. After a lot of experimenting with a mix of transistors, Fets and MosFets the rx worked flawless, using a "plug and play" system without any internal alterations or alignment of the EKB.
I wrote an article describing the project for the Dutch "Surplus Radio Society (SRS). It is written in easy to understand Dutch, but a short English summary is included. The schematics are self explanatory and of course Google Translate is 24h per day standby.

Solidstating DDR rx EKB 19-8-20.docx

[IW1FQG]

Hi, your article looks interesting and well done to me.
A question: does the EKB have something in common with the R5 receiver? It looks similar.

73,
Ugo IW1FQG

[PA0CHS]

Hi Ugo, good evening,

Basically it is the same receiver, but R5 was produced for the Czech army.
Instead of a dedicated AF-headphone connector, the Czechs used bananaplugs.
As far as I know there are technically there are hardly any differences.
The DDR produced also a VHF-set component, which looked almost the same as EKB.
BTW HB9AIK has an interesting R5-site including schematic diagram.

73,

Jan

[IW1FQG]

Ok. Thank you Jan.

Ugo IW1FQG

[IK0MOZ]

Hi Jan, I read that you are SRS Member. I have a lot of friends there (Henk PA0HTT, Louis/PA0LCE, Albert/PA0ERO, Piet/PA0CWF.....) and are in touch with your group from many years. Before SRS I was in contact with IANA/Wim.....
Ciao de Mario