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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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11th Aug 2020, 8:12 pm | #1 |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Help with Invicta valve set
Hi,
Been given this Invictus valve set to play with. It is an old bakelite mains driven set (dropper resistor) and I wonder if anyone might recognise the model so I can find a diagram for it? Photos were a bit of an afterthought, I wanted to attempt a cleanup as it is very sticky, I assume a combination of vigh voltage, wax caps and probably a once smokey atmosphere! It has 5 valves and will get a pic of the back end if that helps. |
11th Aug 2020, 8:27 pm | #2 |
Heptode
Join Date: Apr 2010
Location: West Midlands, UK.
Posts: 663
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Re: Help with Invictus valve set
Invicta Model 200 (According to "Radio Radio" identical to Pye Model 47X).
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11th Aug 2020, 8:37 pm | #3 |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invictus valve set
Thank you sir!
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11th Aug 2020, 10:48 pm | #4 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,642
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Re: Help with Invicta valve set
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12th Aug 2020, 3:42 pm | #5 |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invicta valve set
Would anyone mind offering some advice please?
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12th Aug 2020, 4:00 pm | #6 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,724
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Re: Help with Invicta valve set
At last!
The radio on our kitchen shelf for the first 7 or so years of my life, I had no idea of the make & model until now, just a vague memory. Thanks guys.
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-- Graham. G3ZVT |
12th Aug 2020, 4:14 pm | #7 | |
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Re: Help with Invicta valve set
Quote:
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12th Aug 2020, 4:34 pm | #8 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,724
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Re: Help with Invicta valve set
Looking at the Radio Museum circuit, change the three electrolytic caps, one is prominent on your picture and the other two are mounted on the speaker.
More pictures in this thread https://www.vintage-radio.net/forum/...d.php?t=152716 Change the tubular wax capacitors, but leave the flat ones undisturbed. C23 on the RM sheet is "That Capacitor" change this as a priority. Are you aware of the safety issues when working on live chassis sets?
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-- Graham. G3ZVT |
12th Aug 2020, 4:52 pm | #9 |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invicta valve set
Ta Graham. I was going to replace all the waxy's tbh.
Couple of the Q's I wanted to ask. There appears to be no filter on my radio C27/28 & L7 and wonder if this might have been ripped out when it was rewired or if some radios just didn't have them? Also, R16 in my exaple compromises two 12ishk resistors in parallel. on that very diagram it is a 15k. I was going to replace this with a 15k 3w resitor. Some of my resistors are a little high too so will replace them all. I assume unless stated 1/2 watt metal film should be adequate? |
12th Aug 2020, 4:58 pm | #10 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,642
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Re: Help with Invicta valve set
It's slightly unusual in being permeability tuned. Be careful with the soldering iron!
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12th Aug 2020, 7:21 pm | #11 |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invicta valve set
I am trying not to disturb the mica caps but I was expecting to have to re-align tbh!
This is my first valve radio restoration though. I have done many amps previously but radios have generally not needed touching in the past other than simple straightforward faults! |
12th Aug 2020, 9:28 pm | #12 | |
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Re: Help with Invicta valve set
Quote:
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13th Aug 2020, 9:21 am | #13 |
Heptode
Join Date: Apr 2016
Location: Croxley Green, Hertfordshire, UK.
Posts: 979
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Re: Help with Invicta valve set
I have one of these though mine is the Pye version, this might be of interest-
https://www.vintage-radio.net/forum/...d.php?t=165649
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Clive Last edited by MurphyNut; 13th Aug 2020 at 9:27 am. |
13th Aug 2020, 10:00 am | #14 |
Dekatron
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
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Re: Help with Invicta valve set
The canned electrolytics used for HT reservoir and smoothing are pretty reliable so I would not replace these unless you have confirmed they are faulty. You should bring them gently back to life using a basic capacitor reformer.
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13th Aug 2020, 11:13 am | #15 |
Octode
Join Date: Oct 2019
Location: Stockport, Greater Manchester, UK.
Posts: 1,646
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Re: Help with Invicta valve set
If you, like me, don't have a capacitor reformer there is a post on a cossor 464 thread which explains how to do this. I'm posting a screenshot for you for reference.
I always use a lamp limiter for the initial switch on, it helps me control the voltage better amongst other things |
13th Aug 2020, 3:37 pm | #16 | |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invicta valve set
Quote:
Just waiting for my Farnell order to arrive. Was a bit dissapointed with RS's availability of reasonably priced caps tbh! |
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15th Aug 2020, 8:06 pm | #17 | |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invicta valve set
Quote:
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18th Aug 2020, 12:38 pm | #18 |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invicta valve set
Hi folks Manual says C19 .01 but looking at this cap it is 0.001u?
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18th Aug 2020, 4:25 pm | #19 |
Hexode
Join Date: Dec 2009
Location: South Manchester, UK.
Posts: 262
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Re: Help with Invicta valve set
it's ok the marking was hiding behind some wax. ****** hell it's hard work replacing parts in these little radios!
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18th Aug 2020, 6:30 pm | #20 |
Hexode
Join Date: May 2005
Location: Greater Manchester, UK.
Posts: 498
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Re: Help with Invicta valve set
You can scrape the wax off with a screwdriver and the printing on the paper sleeve underneath becomes clear.
Since you are local to me you are welcome to do the alignment at my workshop if you have not got the equipment. I have a PLL sig generator. Best Regards Chris |