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 Return to top of page · Post #: 1 · Written at 1:55:48 PM on 22 February 2017.
Hamilton's Gravatar
 Location: Adelaide, SA
 Member since 29 January 2017
 Member #: 2051
 Postcount: 5

I have had a life long interest in radio but on the fringe, not a very active roll.
Through these pages I was able to put an approximate year of manufacture of my Father in laws floor standing radio as 1936 as the licence label on the chassis has the letter C, it is a 6 valve with magic eye tuning and for a while I harboured thoughts of getting it going but lots of perusing of these pages has changed my mind, would be a pity to destroy it through ignorance.
Christal sets as a 12 yr old, followed by a failed attempt at a one valve radio [radio & Hobbies ].
In 1955 I took a position as a trainee charge hand with Phillips Electrical at Hendon SA and spent a very interesting 5 months in the Mini Watt section studying all aspects of valve manufacture, but I could not imagine standing all and every day just watching the same bit of the process so I went back to being a Motor Mechanic.
Late 60s I built a Playmaster stereo/ tuner from Electronics Australia but thats as far as it goes. Ralph


 
 Return to top of page · Post #: 2 · Written at 5:24:46 PM on 22 February 2017.
Johnny's avatar
 Location: Hobart, TAS
 Member since 31 July 2016
 Member #: 1959
 Postcount: 320

G'Day Ralph,
With the helpful way this Forum is, you would be able to restore safely the 1936 radio.
It would be a wonderful project provided you have the time.
JJ


 
 Return to top of page · Post #: 3 · Written at 5:43:31 PM on 22 February 2017.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5262

Welcome to V-R, Ralph.

If you let us know the valve types in that console radio we may be able to identify the make and model, if they are not known.

Sometimes there's a valve location diagram on the rear of the chassis. Otherwise, if you have to remove the valves to see what they are, go carefully: pull then out by the bakelite bases, not the glass envelopes, and be very gentle with any valve cap connections. Don't force them off if they don't want to come off.


 
 Return to top of page · Post #: 4 · Written at 10:12:55 PM on 22 February 2017.
Hamilton's Gravatar
 Location: Adelaide, SA
 Member since 29 January 2017
 Member #: 2051
 Postcount: 5

Wonderful, you have given me heart, will note the valve types tomorrow, the manufacturer is not shown anywhere, the cabinet was in disgraceful condition and the best I can say about my efforts is at least moisture wont get into the ply.
When I found it had 8 adjustments on tuning coils I thought that by renewing condensors I would throw all the tuning out of whack. One of the valves has the top cap broken .
Being retired I have stacks of time and am looking for a new project.
Thanks for your encouragement. Ralph


 
 Return to top of page · Post #: 5 · Written at 10:29:59 PM on 22 February 2017.
Tallar Carl's avatar
 Location: Latham, ACT
 Member since 21 February 2015
 Member #: 1705
 Postcount: 1403

Three years ago I had no idea!. Now I still have no idea lol but I can confidently say I can fix that !. Yes this site is very educational and heaps of members here want to help so give it a go and always ask for help.


 
 Return to top of page · Post #: 6 · Written at 8:50:19 AM on 24 February 2017.
Hamilton's Gravatar
 Location: Adelaide, SA
 Member since 29 January 2017
 Member #: 2051
 Postcount: 5

The valve types in this unit are 6A7 [broken] 6D6 6B7 42 80, the magic eye valve has no numbers, made by National Union.
The licence decal on the chassis is C 60629 and heavily stamped into the chassis is 8981.
The 2 aluminium clad electrolytics above the chassis have been disconnected and replaced with a single unit underneath.
When I read of the dangers of powering up an old radio I feel that may be my achilles heel as it looks to have been repaired a few times and how well was it done ? and just how do I tell if its safe to crank it up after changing all the condensers ?
Isnt it silly but I grew up using the word condenser but now have trouble in not saying capacitor.


 
 Return to top of page · Post #: 7 · Written at 11:44:28 AM on 24 February 2017.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5262

Assuming that the magic eye is a 6E5 or 6U5, some candidates are:

AWA 163 (1938) [broadcast band only, no short wave]
AWA 163 (1938)
Columbus 35(1938) .
Hotpoint 458DE (1938)
Lincoln 48 (1937)
National 48 (1937)

Good front and back photos of your set may also aid in identification.

https://vintage-radio.com.au/default.asp?id=image-submission-guidelines

it looks to have been repaired a few times and how well was it done ?

Good question. Plenty of stories on here of sets being "monkeyed with". Checking against the schematic is advised.

and just how do I tell if its safe to crank it up after changing all the condensers ?

First steps are to give a very good looking over for obvious problems such as loose or missing insulation on the point to point wiring (mains cord is usually candidate for replacement), opportunities for shorts around valve sockets (lugs), evidence on components of burning (smell test on transformer), leaky capacitors (replace all electros and paper/wax types as a matter of course).

When all appears safe and well, I use a Variac to slowly apply voltage while paying close attention for any signs of distress. Another technique is to use a dim bulb tester to detect stress on the mains transformer due to short(s).

There are a few V-R members down your way. Maybe one of them could lend a hand. There's also an Adelaide branch of the HRSA.


 
 Return to top of page · Post #: 8 · Written at 7:34:25 AM on 26 February 2017.
Hamilton's Gravatar
 Location: Adelaide, SA
 Member since 29 January 2017
 Member #: 2051
 Postcount: 5

Where in Australia is it possible to buy a 6A7 valve ?


 
 Return to top of page · Post #: 9 · Written at 9:40:27 AM on 26 February 2017.
Tallar Carl's avatar
 Location: Latham, ACT
 Member since 21 February 2015
 Member #: 1705
 Postcount: 1403

Joe Oost in Newtown, or from the HRSA valve bank.


 
 Return to top of page · Post #: 10 · Written at 9:53:29 AM on 26 February 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5502

HRSA Valve Bank is one (membership of the HRSA is required), Ebay is another, posting in the Wanted and For Sale forum is another way. I have about 4,000 valves but they are in another corner of the state at the moment. If waiting about four weeks isn't an issue, and if I have one, and that it shows at 80% or higher on the tester (and also works in a radio) I could let it go for $15 posted.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 11 · Written at 9:58:57 AM on 26 February 2017.
Hamilton's Gravatar
 Location: Adelaide, SA
 Member since 29 January 2017
 Member #: 2051
 Postcount: 5

Thank you Tallar Carl and GTC for your help, I have just opened my eyes to a glaring and dangerous fault with this device {how many times ive seen but not thought } The power cord is directly soldered to the transformer input and has no earth wire meaning that every output of the transformer is live whenever the power point is on, also with no earth I reckon our earth leakage device wouldnt work, just how much more there is to find ? I think its too dangerous for an elderly mechanic to fiddle with.
Thanks again guys . Ralph


 
 Return to top of page · Post #: 12 · Written at 10:20:48 AM on 26 February 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5502

also with no earth I reckon our earth leakage device wouldn't work

It depends on what sort of earth leakage device it is. Back in the 1950s, some county councils in NSW were fitting voltage-operated earth leakage circuit breakers as main switches to meter boxes. One switch would cover the whole house. They worked simply by sensing a voltage in the earthing system and tripped the power to the whole house accordingly. Unfortunately, the only way they could protect a shock victim was if the appliance was earthed and the fault current passed from active to earth via the victim's body. The big downside to these is that local lightning strikes would also trip them.

If it is a more modern, DIN rail form factor current-operated core balance relay, also known as an RCD or 'safety switch', then the protection is a little better. It works by sensing an imbalance of current between the active and neutral wires. A shock victim upsets this balance and the switch trips. For this type of switch to work, the fault current can pass from active to the earth of the appliance or from active to any other 'earthed' connection (EG: bare feet on a concrete floor).

Neither switch will work for shocks that take only an active to neutral path and neither switch will work for shocks received on the secondary side of an isolation transformer. This means if you cop the approx. 700V from the HT winding of the average Australia valve radio then you are out of luck. I did once, when I was a lot younger. It hurts. Lesson: be far more careful next time.

As for your radio - direct soldering of cords was the most common type of connection. There were rules at the time that if a power switch was fitted to an appliance then it had to be a double-pole type. Some manufacturers fitted line switches as an extra cost option in the middle of the power lead and most just didn't fit anything to keep costs down, so radios were just controlled from the power point or plugged/unplugged from a bayonet socket as needed. There is nothing really wrong with connecting your new cord in the same manner though a grommet and cable clamp will need to replace the knot in the existing cord for compliance reasons. You could also use a cable gland but these look too modern on vintage equipment. I always use a grommet and a cable clamp for authenticity.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 13 · Written at 8:00:05 PM on 27 February 2017.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 570

Hi Ralph, just regarding two points,

1/ The power cord. Procure a THREE wire cord with a GREEN earth wire. Pinch the wife's toaster cord, buy one from Jaycar whatever, just so long as it has a green wire. Unsolder whatever is fitted and replace with the new cord, hook the hot wires , the red/black or blue / brown ( what idiot thought up those colours?) to the transformer and connect the GREEN wire to the chassis. For the earth connection, solder the wire to the chassis, or bolt a solder lug to the chassis using a spare hole, or drill a hole. It is illegal to use an already used bolt but better than nothing. THEN TEST the connections by ensuring that the EARTH pin on the plug is connected back to the chassis. DO NOT assume the plug is wired correctly. Fit a clamp of some sort to the cord to stop it pulling out of the chassis like a power cord clamp or a bulkhead gland from Jaycar. You now have a 3 wire set.

2/ The switch. From Bunnings or Woolworths or even an electrical shop, if you can find one, buy a power block with a switch even if it is 4 hole outlet. Plug the set into that and the power block into the mains. Now use the power block switch as ONLY the set switch. Gaffer tape the block to the set if necessary. (Safety before originality.)

YES I know, the switch is only single pole and we have not discussed active and neutral as if most people would know the difference but now you are EARTHED and have a SWITCH.
THEN follow the power up advice as given by the members.

Cheers, Fred.


 
 Return to top of page · Post #: 14 · Written at 9:40:03 PM on 27 February 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5502

Just as a clarification, it's not legal to use a flex with a green earth lead. It needs to be the modern green/yellow colour combination.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 15 · Written at 8:14:17 AM on 28 February 2017.
Johnny's avatar
 Location: Hobart, TAS
 Member since 31 July 2016
 Member #: 1959
 Postcount: 320

Soldering the earth wire to an existing earth point is also a no no.
Tinning with solder before crimping onto a lug bolted to the chassis is also a no no.
Should be bolted with a locknut and star washer with screwdriver slot not directly accessible to user.
And of course the cable properly retained. No knots.
JJ


 
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