UNITRA DG-203 help - UK Vintage Radio Repair and Restoration Discussion Forum

Drroberts1952 · 13th Oct 2021, 2:22 pm

Hello out there. Can anyone help me with this Polish unit. I’m trying to work out how the phono is amplified at the main chassis. I don’t have the deck here but I’ve hooked mine up to the phono in and the signal is very poor. Does this unit have a phono stage amplifier with the deck? Anyone got a schematic?

peter_sol · 13th Oct 2021, 4:58 pm

This is unlikely to be for a magnetic cartridge only a medium output crystal type.

roffe · 13th Oct 2021, 6:08 pm

https://www.oldradio.pl/karta.php?numer=363

The same as Unitra Diora Meteor 2?
Circuit diagram:
https://elektrotanya.com/meteor-2_am...wnload.html#dl

Edward Huggins · 13th Oct 2021, 7:45 pm

Well the ECL86 will only work with a ceramic/crystal cartridge, so I suspect the OP is trying to play a MM into it. Result = very low output.

Drroberts1952 · 13th Oct 2021, 8:10 pm

That schematic looks really helpful. Thanks. I’ll let you know how I get on

Drroberts1952 · 15th Oct 2021, 8:56 pm

Quote:

Originally Posted by Edward Huggins

Well the ECL86 will only work with a ceramic/crystal cartridge, so I suspect the OP is trying to play a MM into it. Result = very low output.

I think that’s spot on. I’m a bit confused because I expecting be able to adjust the output of my signal generator to about 3mV and get amplified signal. But it does need much more than that. Have I miscalculated the o/p if a Crystal cartridge? Thanks by the way

Drroberts1952 · 15th Oct 2021, 9:01 pm

Just looked at specs for Crystal cartridges. Now I get it! 200mV not unusual

13th Oct 2021, 2:22 pm	#1
Drroberts1952 Triode Join Date: Sep 2021 Location: Liskeard, Cornwall, UK. Posts: 12	UNITRA DG-203 help Hello out there. Can anyone help me with this Polish unit. I’m trying to work out how the phono is amplified at the main chassis. I don’t have the deck here but I’ve hooked mine up to the phono in and the signal is very poor. Does this unit have a phono stage amplifier with the deck? Anyone got a schematic?

13th Oct 2021, 4:58 pm	#2
peter_sol Octode Join Date: Aug 2003 Location: Welwyn Garden City, Herts. UK. Posts: 1,906	Re: UNITRA DG-203 help This is unlikely to be for a magnetic cartridge only a medium output crystal type.

13th Oct 2021, 6:08 pm	#3
roffe Hexode Join Date: Nov 2003 Location: Linkoping, Sweden Posts: 493	Re: UNITRA DG-203 help https://www.oldradio.pl/karta.php?numer=363 The same as Unitra Diora Meteor 2? Circuit diagram: https://elektrotanya.com/meteor-2_am...wnload.html#dl

13th Oct 2021, 7:45 pm	#4
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,336	Re: UNITRA DG-203 help Well the ECL86 will only work with a ceramic/crystal cartridge, so I suspect the OP is trying to play a MM into it. Result = very low output. __________________ Edward.

13th Oct 2021, 8:10 pm	#5
Drroberts1952 Triode Join Date: Sep 2021 Location: Liskeard, Cornwall, UK. Posts: 12	Re: UNITRA DG-203 help That schematic looks really helpful. Thanks. I’ll let you know how I get on

15th Oct 2021, 9:01 pm	#7
Drroberts1952 Triode Join Date: Sep 2021 Location: Liskeard, Cornwall, UK. Posts: 12	Re: UNITRA DG-203 help Just looked at specs for Crystal cartridges. Now I get it! 200mV not unusual