[Premium-Rx] SRT CR302A EJ KANB 301A

[Peter Ratuschni]

Hello All,
yesterday I received a swedish HF receiver, a SRT CR302A. (This was for heavy but luckless repairing of the Eddystone.) SRT means "Standard Radio and Telephone".
The label "302A" was hidden by a sticker saying "EJ KAN B 301A". 
A switchs allows the following modes: A1.1, A1.2 (CW), F1.1, F1.2 (seems to be the FSK option), A2.A3 (AM), A3AU (USB), A3AL (LSB), A3B (DSB ?). Some more positons are possible which are not marked.

Does anybody knows about this unit? On the web there is only some very basic information.

There is a switch with 11 positions, going from AGC to Chan.A, Chan.B and numbers from 1 to 8. I am not sure what this is good for. It is not HF gain because manual gain control is done with a potentiometer below and activated with a push button.
The display consists of 6 nixie tubes in original but somebody swapped the 4 lower digits with big LED digits. That looks strange, but after a while I liked it. Then the tuning seems to be also modified. The original unit has a switch for each digit - you have to move to another switch if you want to change from i.e. 7,999.9 KHz to 8,000.0 KHz. So instead of a 100Hz step you can produce a step of 1 MHz. (First nulling the 4 lower digits and then incrementing the MHz-digit). I do not know if this is originally the same with every digit - on mine unit two switches were omitted and the 100Hz tuning knob is able to make a carry for 1, 10 and 100 KHz. The control of the LED digits is realized with a DIY pcb. 
The internal 5 MHz reference was a little surprise to me, as this seems to be a big OCXO. I do not know if this was usual for commercial receivers that time.

I fiddled around a bit with this heavy unit and found that I never heard CW so good at my location. The area is electromagnetically polluted in the sw range and I have only some indoor antenna wire. Of course, with wider filters I found nearly the same problems as with the other receivers.

b.r.
Peter