General Discussion

Forum home - Go back to General discussion

AWA Wooden Mantle Radiola
« Back · 1 · 2 · 3 · Next »
Return to top of page · Post #: 31 · Written at 10:25:41 PM on 15 October 2017.
	Tallar Carl Location: Latham, ACT Member since 21 February 2015 Member #: 1705 Postcount: 2155
Dont worry Marcc I have never ever been cavalier with electricity . I dont think I will have any issues identifying the varios output wires its just the inputs that will be a little issue to me but I will not do anything with out the technician that teaches me having a good look. One of the things I am going to do with this cabinet is try Howards Restore a Finish on it. The yanks swear by it . I will let you all know how it goes.

Return to top of page · Post #: 32 · Written at 10:52:30 PM on 15 October 2017.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5254
With the normal sort of old valve radio transformer these are much easier to get along with, if they are unmarked. Heater & filament windings are obvious from the heavy wire. The HV secondary is centre tapped & will be very close in ohms each side. The primary tappings are close together. ie only a few ohms apart. I rarely use a Variac on a 240V transformers more often via the isolation transformer, as it has a kill switch. 110V radio's: Stepdown transformer.

Return to top of page · Post #: 33 · Written at 11:48:38 PM on 15 October 2017.
	GTC Location: Sydney, NSW Member since 28 January 2011 Member #: 823 Postcount: 6687
wouldnt the 110 volt setting produce the same output as the 240 volt setting I wasn't clear enough: connect Variac to secondary and measure the primary. I have dozens of unidentified transformers in my shop. I use the Variac and meter to suss them out and label them. Naturally, you need to take sufficient care when you have a step up situation.

Return to top of page · Post #: 34 · Written at 1:48:43 PM on 16 October 2017.
	STC830 Location: NSW Member since 10 June 2010 Member #: 681 Postcount: 1256
My practice with unknown transformers is to identify the primary (easy if it has black and red wires attached, more difficult if it doesn't, or if there are taps for various mains voltages), attach 24 volts AC to this presumed primary winding, and read off the secondary voltages, which will be one tenth of the service voltage, and much safer than the full unloaded service voltage. Look for the heaviest winding which should read a little more than 0.63 volts since it is unloaded (one tenth of the service heater voltage of 6.3 volts); if that is found the the primary selection is probably right. Then look for 0.5 volt winding if it has one, and the HT winding which will have the highest voltage and has a center tap. If you don't have exactly 24 volts, the maths is easy to calculate what the heater winding voltage should be to get started, and to calculate the other outputs.

Return to top of page · Post #: 35 · Written at 4:00:54 PM on 1 November 2019.
	Tallar Carl Location: Latham, ACT Member since 21 February 2015 Member #: 1705 Postcount: 2155
Well after all this time the cabinet is finished and back to its former glory will send Brad some photos. Got lots of projects on the boil.

Return to top of page · Post #: 36 · Written at 8:33:21 PM on 3 November 2019.
	Brad Administrator Location: Naremburn, NSW Member since 15 November 2005 Member #: 1 Postcount: 7302
Photos uploaded to Post 35. ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ A valve a day keeps the transistor away...

Return to top of page · Post #: 37 · Written at 8:38:57 PM on 3 November 2019.
	GTC Location: Sydney, NSW Member since 28 January 2011 Member #: 823 Postcount: 6687
Cabinet looks good. 👍

« Back · 1 · 2 · 3 · Next »
You need to be a member to post comments on this forum.

General Discussion

Sign In