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 Identifying Console Radio
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 Return to top of page · Post #: 1 · Written at 10:38:04 AM on 28 April 2019.
Wirelessfan's avatar
 Location: Sydney, NSW
 Member since 26 April 2019
 Member #: 2349
 Postcount: 18

Would appreciate help in identifying free standing console radio.

Markings on the circular dial are partly missing, but could be possibly "Croyden".
ARTS&P sticker showing "No. 4, Dxxx" Serial number is stamped H4738.
It has metal octal valves with a 6J7 autodyne convertor with what looks another 6J7 as detector, no AVC. 6V6, 80. IF is 6k7.
The design seems non-conventional in that the speaker field seems to be in the return circuit to ground.
Any ideas about this unit?

Thanks


 
 Return to top of page · Post #: 2 · Written at 11:57:05 AM on 28 April 2019.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5262

Croyden was a brand of Eclipse Radio Pty Ltd.

I can't find anything with that particular line-up. Are you sure those are the correct valves? People do stick anything into a radio to make it look right.

PS: What is the colour of the ARTS&P sticker?


 
 Return to top of page · Post #: 3 · Written at 2:35:18 PM on 28 April 2019.
JFB's Gravatar
 JFB
 Location: Milton, NSW
 Member since 27 June 2016
 Member #: 1945
 Postcount: 35

Probably displaying my own ignorance here but how else does one learn - the "D" prefix on the ARTS&P suggests 1937, the round dial also suggests 1930's. If this is true the colour of the ARTS&P should be pale blue.

The HSRA radio models spreadsheet suggests a typical valve lineup for Croyden at the time as something like 6A8, 6K7, 6J7, 6F6, 80. Close but not quite.

Certainly I would not expect to see a 6V6 in that era given that it was only released in 1936 and I note that Croyden was still using 6F6s as the output valve as late as 1940.

Croyden appears to have quite a number of console models around that time, 524, 544, 547 & 550 among them. They all appear to be using the same chassis 465 (for five valve sets). Any of these or similar numbers stamped on the chassis?

Might be possible to narrow it down a bit - is it BC only or Dual wave?. AC only or AC/DC.

The museum site lists many of the models, many with schematics but no pictures unfortunately.

Joe


 
 Return to top of page · Post #: 4 · Written at 5:17:12 PM on 28 April 2019.
Wirelessfan's avatar
 Location: Sydney, NSW
 Member since 26 April 2019
 Member #: 2349
 Postcount: 18

BC only, AC only. There is no number stamped apart from the H4748.

Possibly tubes are not all the originals- a 6B6G was found plugged in not working-but the original wires show pin 5 linked to 8 so I am assuming this should be 6J7.
6J7 as convertor seems correct, pin5 linked to 8, with cathode running off to osc coil, is oscillating ok.

Chassis is a bluey-green, ARTS&P sticker seems pale blue.

Eclipse Radio Melbourne-set came from country Victoria, there is a service(?) sticker on the back of the chassis "JD Mackintosh- ESTD 1930 Radio Sales and Service, Television. 102 Sydney Rd Brunswick phone FW8844"


 
 Return to top of page · Post #: 5 · Written at 5:35:42 PM on 28 April 2019.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5262

A circular "aeroplane" type dial is consistent with late 1930s. Maybe some well-lit, in-focus photos of front and chassis could help identify it.


 
 Return to top of page · Post #: 6 · Written at 5:37:53 PM on 28 April 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3707

6J7 will not be the converter unless its an autodyne and if 6B6 is correct it is unlikely to be an autodyne. 6J7 is a Pentode amp normally used as a biased detector. 6B6 is a double diode triode & it would be the detector. Pentagrid 6J8, 6K8, 6A8, perhaps. 6J8 after 1939.

Model EKR Eclipse used a 6J8 followed by another. How many valves does it have provision for?


 
 Return to top of page · Post #: 7 · Written at 7:24:27 PM on 28 April 2019.
Wirelessfan's avatar
 Location: Sydney, NSW
 Member since 26 April 2019
 Member #: 2349
 Postcount: 18

I confirmed that the detector works with 6J7plugged in-fart test ok- plenty of gain, good output!
Output tube may have been originally 6F6, must check the bias.
The converter has pin6 never soldered, so never had 6J8, this model radio could be a possible variant.


 
 Return to top of page · Post #: 8 · Written at 8:50:54 PM on 28 April 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3707

6J8 was one of the last octal converters made so would not be in anything early. 6J7 is the same as 57 but with a different heater & base.
57 was a common Autodyne (Screen grid) mixer valve. It would not be unreasonable to use 6J7 again as a biased detector & the tube data files have the data for that application. It should, as a biased detector have a very high value cathode resistor.


 
 Return to top of page · Post #: 9 · Written at 6:52:31 AM on 29 April 2019.
Wirelessfan's avatar
 Location: Sydney, NSW
 Member since 26 April 2019
 Member #: 2349
 Postcount: 18

Seems that to restore this console, which I now know as a Croyden by Eclipse Radio Pty Ltd., made in Melbourne 1937.
AC, BC only. 5 valve Superhet. with Autodyne converter, Anode bend detector.

...I need to get a 6J7(metal preferably), 6F6 and 2x 6.3v dial lights, all of which I do not have. Time to start searching....

Many Thanks to the above posters for their valuable insights.

Cheers.


 
 Return to top of page · Post #: 10 · Written at 4:14:40 PM on 29 April 2019.
JFB's Gravatar
 JFB
 Location: Milton, NSW
 Member since 27 June 2016
 Member #: 1945
 Postcount: 35

If we accept my earlier wild guess - that it's 1937 then since it's AC only, BC only and a console then it's either a 524 or a 544 both of which use the same chassis 524. Unfortunately neither model number leads to any photo's or schematics that I could find. Nor can I confirm that the valve line up on these models is as I suggested earlier.

If we assume the (guessed) valve line is correct then there is schematic of a mantle model from Croyden in that year that may provide useful information. Downloadable from https://www.radiomuseum.org/r/eclipse_croyden_572.html
It's for a model 572 mantle, but right year, right manufacturer, possibly right valve line up, hopefully the same or similar chassis

Joe


 
 Return to top of page · Post #: 11 · Written at 8:16:43 PM on 29 April 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3707

572 uses a 6A8 which is a Pentagrid. However, the 1st IF onwards from that will possibly be the same. The 57 "screen grid" setup was fairly standard: Fixed quite few.

Marc


 
 Return to top of page · Post #: 12 · Written at 12:23:59 PM on 19 May 2019.
Sirwin's avatar
 Location: QLD
 Member since 10 April 2009
 Member #: 465
 Postcount: 101

According to my list, the model 544 uses: 6J7 autodyne converter, 6K7 I.F. amp., 6J7 detector, 6F6 output, 80 rectifier. I have found evidence that it came out in 1935 but may have been still in production in 1937. The 524 of 1935 seems similar but uses 2.5 volt valves. I'd say the model was released to cash in on the latest craze: metal valves, by simply modifying the existing 524 to use them. In any case it is a bit of a throw back to the autodyne, anode bend detector days of 1933. However, some people did prefer no AGC and anode bend detection because it gave the impression of having great selectivity. I hope that may shed some light.


 
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