Jara "Krysatec" ("Rat") from Czechia

Hi Dave,
I send you some my pictures, maybe it will be interesting for you.
AF7 is receiver (audion) with one AF7 tube and with changed coils (first picture_
ECH21 is MW receiver with feedback (left) and 1L33 is crystal radio with two 1L33 audioamplifier (right)
EM83 is MW receiver with double magic eye EM83 (EMM801). (Here I send you also schematic)(last picture)

Hi Dave!

Last night I built my new receiver with a tube! I don'thave any photos now, because I don't have a camera, but if you are interesting also in photos, I can send photos next week.

I'm sending you a schematic of simple receiver with russian tube 6H16b (6N16B). I dont know it sure, but I think this tubes was used for instance in old MiGs (Mikhojan-Gurewitsch) jet figters.

Maybe it will be interesting to you, because result is very good! Sensitivity is better as my reflex with two Ge transistors with feedback, selectivity too, I think, that only audio volume is a little lower. But you can use 15V voltage (you must change resistor 15R and use cca 20R!) and here is audio volume the same as with transistors. Positive feedback is very good, very fine, I think as in Ramon´s transistors receiver. Only one problem is high current for the heater (400mA) , but I don't have other better tube for tests.

I use only one voltage, 12V for all, heating voltage is 6V and I use resistor serial with the heater. Other and better idea is 7806 stabiliser. You can use also 24V voltage with him.

Regards,
Jara "Rat" Czechia

More Projects From Krysatec

Krysatec's Testboard And Power Supply

Jara "Krysatec" ("Rat") from Czechia - EM84 Radio

Hi Dave!

I'm sending you some pictures of my constructions and also schematics and picures of my receiver with one tube EM84 magic eye!

Receiver works good with nearby stations, but I've heard also stations from other counries in Europe (in the day, but in night it is better, I hear stations also from Near East, because in NE are stations with EIRP 1-2MW too... /Saudi Arabia etc/)

Here is only one triode and audio is worse than with dual magic eye EM83/EMM801. But receiver is not for DXing...

I tested two version: with ferrite rod and fixed positive feedback and with air core coils with variable feedback. This is better.

You can use crystal earphone or 4k Ohm earphone, but it work also with my old "czech made" earphone with 2x75R speakers!

S pozdravem,
Regards,

Jara "Krysatec" ("Rat")

Very nice Jara. I like the variometer type coil that you updated your receiver with. I hope to make my EM84 receiver soon.

Dave