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 ASTOR S GN MODEL SCHEMATIC NEEDED!
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 Return to top of page · Post #: 1 · Written at 2:45:37 PM on 30 August 2009.
Leeinv66's Gravatar
 Location: Launceston, TAS
 Member since 30 August 2009
 Member #: 538
 Postcount: 27

Hi, I am fairly new to tube radio repair. I have rebuilt a few (mostly American midgets), but I am currently working on a six tube multi band Astor I picked up locally. The closest I can find to it on the web is a 1950’s GN model. Although, this one is in a wooden rather than a bakelite case. I have had no luck finding a schematic and as this radio has a lot of problems, I am going to need one. Can anyone point me in the right direction to find this schematic?

Thanks
Peter


 
 Return to top of page · Post #: 2 · Written at 7:57:33 PM on 30 August 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Astor GN is listed in AORSM's

The number should be stamped on its chassis.

If its a GN it would have 5Y3, 6V6, 6B6, 6U7, 6J8 or 6AN7. Which does not compute.

If its
6N8, 6AN7, 6N8, 6AV6, 6AQ5, 5Y3GT then its likely an NM and this is stamped on the top rear of the chassis, on the edge near the output tube. I have a post looking for circuit for NM. Meantime I have got it running.

If its one of these, a good long aerial, will overload the front end on a really close station.

If its anything like the one I had. Replace all of the paper & electrolytic caps & watch the resistors; I replaced nine of them. Do that then look for the fault (you may not then have it).

6N8 is a dreadfully unreliable valve.

Marc


 
 Return to top of page · Post #: 3 · Written at 1:19:28 PM on 31 August 2009.
Leeinv66's Gravatar
 Location: Launceston, TAS
 Member since 30 August 2009
 Member #: 538
 Postcount: 27

Hi Marc, thanks for the reply, but now I am not sure what I haveSmile

Marked on the chassis is WNS 553A (the A is scratched on while the rest is stamped). Part of the reason I want a schematic is two of the tubes have no markings. Here is what I can make out: ?, 6AV6, ?, 6J8GA, 6K7G, 6V6GT. The only reason I thought it was a GN was that it had the same grill, so I am probably way off base.

Thanks
Peter


 
 Return to top of page · Post #: 4 · Written at 10:59:00 PM on 31 August 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Some Astor's seem to have escaped AORSM's.

There is some chance that wrong valves have been fitted.

6K7 may have been 6U7: 6J8 may have been swapped from a 6A8?

What are the missing tubes Octal or Minature? 6AV6 is a minature

I would expect one to be the rectifier possibly a 5Y3GT? perhaps 6X5

You are implying there are six valves?

6J8 is going to be the converter
6K7 is an RF Amp
6AV6 is the detector & first Audio.
6V6 is going to be the audio amp,

This leaves a missing rectifier and probably another RF tube, which may be the same as the other RF valve.

If my plot is correct, I also expect a 3 Gang tuner and possibly SW.

I am leaning toward some version of a deluxe six.

Marc


 
 Return to top of page · Post #: 5 · Written at 1:21:30 PM on 1 September 2009.
Leeinv66's Gravatar
 Location: Launceston, TAS
 Member since 30 August 2009
 Member #: 538
 Postcount: 27

Hi Marc,

Yes it is a six tube set and yes, it has a three gang tuner. It also has a four positions band switch. I have all six tubes and five are Octal and one is a mini (the 6AV6). The two tubes represented by the question marks have no numbers on them.

I also wondered if the tubes were right, hence the reason I was looking for a schematic. However, they all seemed to be as dirty as each other, so they could be right for all I know. I can supply a picture of the chassis if that will help? I'll try to attach a link to them as I am not sure I can upload them to this site.

http://i10.photobucket.com/albums/a142/leeinv66/100_0751.jpg

http://i10.photobucket.com/albums/a142/leeinv66/100_0752.jpg

Thanks
Peter


 
 Return to top of page · Post #: 6 · Written at 1:24:18 PM on 1 September 2009.
Leeinv66's Gravatar
 Location: Launceston, TAS
 Member since 30 August 2009
 Member #: 538
 Postcount: 27

Sorry, the links did not post as live links. If you cut and paste them into your browser, they will work.

Thanks again
Peter


 
 Return to top of page · Post #: 7 · Written at 3:39:29 PM on 1 September 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

If you want to post photo's send to Brad. He can also send them to me.

6J8 will be correct for a sw.

The 1958 deluxe six (NM) was a multi band. This is looking like one of the variants.

The rectifier is easy to identify especially if its a 5Y3; That if it's the old "RCA type" ?

It will have two distinct tubes (like a duct) with the filament looping to a point at the top, in each tube (plates). Try not to run that valve sidways, if the filament sags, they blow.

Put them in the freezer for a few minutes & look carefully when you take it out. Often the moisture will reveal the number.

I would suggest that the other valve is going to be as suggested, RF and may look exactly the same as the 6K7

Don't panic I fixed the Deluxe six (and many others) without a circuit

Marc


 
 Return to top of page · Post #: 8 · Written at 7:48:44 PM on 1 September 2009.
Leeinv66's Gravatar
 Location: Launceston, TAS
 Member since 30 August 2009
 Member #: 538
 Postcount: 27

Yes Marc, I can see this set has much in common with the Deluxe six you posted about. I tried the freezer trick with the tubes, but I had no luck finding any numbers.

The rectifier is a Phillips Miniwatt . The other RF tube looks a little different to the 6K7. But the 6K7 is a Miniwatt and the one missing the number is an RCA, so it is difficult to know if they are the same.

This set has suffered rodent damage, so I have a fair few things to put right before I know where I am with it. I have started replacing the caps and some wiring and need to replace the choke (the one mounted near the transformer) as it has been chewed to pieces. I was told to replace the choke with a 2000 ohms, 5 watt resistor. Do you know if this would work?

Thanks again
Peter


 
 Return to top of page · Post #: 9 · Written at 12:19:11 AM on 2 September 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

The different valve manufacturers often used slightly different construction.

Substituting chokes with resistors is common practice. It would be handy if someone else with knowledge of the set & choke, would get involved.

I would tend to use two 4K7 WW in parallel & see what voltage you get
Most of those sets ran at around 250VDC, after the choke. How badly did they turn the choke into "ratatui"?

If you have a 6J7 or 6U7 compare it to them. If the numbers have not been obliterated sometimes, the right angle of reflection from sunlight can work. Circuit would be even better ..... I'm still looking.

Pool soda ash (Sodium Carbonate not Sodium Bi Carbonate aka Baking soda) mixed with a few drops of dishwashing liqiud, will remove mouse excretia from the chassis and the open contruction wafer switches. Do not leave this stuff on the switch long.

Clear with clean water & water displacer albiet just soaking up the water & letting the thing dry will work. Try to keep aqueous cleaner out of the transformers & trimmers.

Marc


 
 Return to top of page · Post #: 10 · Written at 6:27:39 PM on 2 September 2009.
Leeinv66's Gravatar
 Location: Launceston, TAS
 Member since 30 August 2009
 Member #: 538
 Postcount: 27

Thanks Marc!

Yes, the choke is complete "ratatui"!!! Looks like the criter chewed through just about every layer. I'll try the two resistors in parallel as you suggest. I at least know the voltage to look for now, so that is a real bonus! Thanks! I post back later and let you know how it turns out.

Peter


 
 Return to top of page · Post #: 11 · Written at 9:27:56 AM on 3 September 2009.
Gfr53's Gravatar
 Location: Harston, VIC
 Member since 28 February 2009
 Member #: 442
 Postcount: 145

G'day Peter,

Astor produced a WNS all wave in 1951. The valve lineup was; 6U7G, 6J8GA, 6U7G, 6AV6, 6V6GT and 5Y3GT.

They also made an amended version (WNSA?) using either a X61M or a 6J8GA as the convertor.

I believe there is a circuit for both these models in the 1951 edition of the AORSM on pages 49 and 51. I'll have a look this evening and confirm. Do you require a copy of these pages, or do you have that manual?

Cheers, Graham...


 
 Return to top of page · Post #: 12 · Written at 9:57:37 AM on 3 September 2009.
Gfr53's Gravatar
 Location: Harston, VIC
 Member since 28 February 2009
 Member #: 442
 Postcount: 145

Peter, Forgot to mention that the WNS is the wooden cabinet version of the NS and NSA models with the same circuits.

Pages 49 and 51 of the AORSM are valid for both models.

Cheers, Graham...


 
 Return to top of page · Post #: 13 · Written at 8:26:48 PM on 3 September 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Graham

Thanks for that info; You have provided the missing link. We now have a result.

I too have an NS circuit and indeed that confirms my suspicion that the 6K7 was a ring in. Having said that, it its not that disimilar to a 6U7 electrically, to the point that I will stick my neck out & say that it should work and had been.

The good thing is that the circuit has voltages plastered all over it, so there is every chance that we can establish the DC resistance of the choke. From this the wattage & value of the resistor to replace it.

Marc


 
 Return to top of page · Post #: 14 · Written at 11:51:18 PM on 3 September 2009.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Took a good look at those circuits. One has been modified so that there is a resistor, not a choke. Its 2 x 5K 1 Watt in parallel (no longer available)

I would tend to use 2.4K 5W and consider 100 Ohm in series with it. It is better to er lower than higher as its SW and 6J8 likes its 250 VDC. Make sure all of the resisors on it are good.

I also note that the power for the Plate of the 6V6 comes straight off of the 5Y3, before the resistor. The screen after. That's fine the plate does not amplify and the screen is lower at that plate voltage.

What may get you zapped if you are not careful and yours is wired similar? The output transformer (not unusual) frame is at HT (B+).
Unless it is an ISO (insulated in can) look out..... don't touch it. It may be insulated fron the chassis, in other words ....... very alive!

Marc


 
 Return to top of page · Post #: 15 · Written at 12:56:11 AM on 13 September 2009.
Leeinv66's Gravatar
 Location: Launceston, TAS
 Member since 30 August 2009
 Member #: 538
 Postcount: 27

Hi Marc and Graham, Sorry for the late reply but I was hving too much fun working on this radioSmile I thought I had it under control, but now I am not sure.

First, I have the set running, but with an issue. I took a gamble and installed a 2.5K 5W resistor to replace the choke as I had one and that seems to be working fine. It had very low volume and it didn't seem I was getting enough voltage out of the rectifier. I had a 5Y3GT on hand and knowing that 5Z4, 5W4, 5Y3 and 5V4 (five volt filament with the same pinout rectifiers) are interchangeable in many cases, I plugged it in and it perk up but was still a little low on sound.

As I could buzz the speaker by touching the connecter on the volume control and that produced a much louder sound than the signal seemed to, I started to suspect one of the RF tubes might be soft. Any way, as Marc said the second RF was probably the same as the first one, I swapped them around and got another increase in the volume. It is all most at the point where I am satisfied with the volume, and I ordered another pair of 6K7Gs as I thought one of them was soft and with that replaced, I'd be home and hosed.

But now I'm not sure that will be the case as it sounds like the 6K7G is a ring in. I guess I will know for sure when the new ones arrive! If they don't work, I'll order a pair of 6U7Gs.

Graham, no I do not have a copy of the AORSM and would appreciate it if you could send me a copy of those pages. The year 1951 sounds right for this set as that date is stamped on both the choke and the speaker coil. Thank you for helping me pining down this ones details!

Marc, I fell like a bit of a dill, I finished restoring the case for this one today and the last thing I did was clean the dial plate. Guess what is stamped on it, twice in fact? Yes, you got it, De-luxe Six.

Thanks guys for all the information. This set has proved to be a great learning experience, if nothing else! Ah, it also looks pretty good with its new finish and painted grill.

All the best
Peter




 
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