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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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7th Nov 2017, 10:38 am | #21 |
Tetrode
Join Date: Jan 2017
Location: Mansfield, Notts, UK.
Posts: 77
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Re: Pye 15A capacitor question
I was interested to read about the differences on the EBL31 posted by Neil. In one of the sets there is a larger version. Seems like the original top cap connection has been forced onto the larger valve making it a very loose fit.
Nick
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7th Nov 2017, 11:05 am | #22 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Pye 15A capacitor question
Zaerix...Z & I Aero Services...a popular supplier of valves from various sources back in the day.
Lawrence. |
7th Nov 2017, 11:55 am | #23 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
Posts: 2,083
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Re: Pye 15A capacitor question
That Zaerix valve still has the top cap diameter of a EBL1, but has a new IO base.
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7th Nov 2017, 2:03 pm | #24 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
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Re: Pye 15A capacitor question
I think I can see traces of the Philips red paint/screening on the Zearix valve envelope too.
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7th Nov 2017, 2:21 pm | #25 |
Banned
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
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Re: Pye 15A capacitor question
The Zearix looks to be an early EBL1, side contact, possibly Philips that has a converted base. Its a bigger bottle than the later ones.The base is the wrong colour for a Mullard. Zearix were a re-labeling outfit who bought valves from many different makers.
Changing the base may have just been a new octal cap over the remains of the side contact, changing the top cap on the pip would be a more ticklish job, hence they left the larger cap on. If you need any, I have both sorts of EBL31 and some EBL21 |
7th Nov 2017, 4:24 pm | #26 |
Tetrode
Join Date: Jan 2017
Location: Mansfield, Notts, UK.
Posts: 77
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Re: Pye 15A capacitor question
Boater Sam, many thanks for the kind offer. You are correct in saying that the top connection on the two valves in the pic on my previous post are of different sizes. There was originally red screening paint on the larger valve but it was peeling off and hanging over the base and fell off as I removed the valve.
Having now replaced the suggested capacitors and brought the set up using a lamp limiter it is now working, much to my amazement. It does not appear very sensitive, I am using about 15ft of indoor aerial at the moment, long wave R4 is reasonable, anything on MW is quite feint. Would that be due to short aerial or other potential problem with the set? Nick
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7th Nov 2017, 4:29 pm | #27 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
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Re: Pye 15A capacitor question
MW reception should be better than LW with the aerial you are using.
Short superhets like these do benefit from a decent aerial, but it sounds as if you have a problem, maybe something as simple as a dirty wavechange switch. Is it still insensitive with the lamp bypassed? |
7th Nov 2017, 4:33 pm | #28 |
Tetrode
Join Date: Jan 2017
Location: Mansfield, Notts, UK.
Posts: 77
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Re: Pye 15A capacitor question
Yes it is now running without the lamp limiter in circuit. I will check the wavechange switch later and report back.
Nick
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8th Nov 2017, 9:16 am | #29 |
Tetrode
Join Date: Jan 2017
Location: Mansfield, Notts, UK.
Posts: 77
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Re: Pye 15A capacitor question
As a follow up to my previous post, I noticed that the three A15s I have all have different valves in V1 position. One is ECH35 as shown on valve label attached to chassis, one is CCH35 and that is the one running in the set I am working on now with low sensitivity and the third has a CV1347. I have tried the other two in place of the CCH35 but I don't get any stations with those in. I don't know if either are ok or dead valves at the moment though. Question, is the CCH35 a direct replacement or will the wiring to the valve base likely to have been changed?
Nick
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8th Nov 2017, 9:55 am | #30 |
Dekatron
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Location: Warnham, West Sussex. 10 miles south of DORKING.
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Re: Pye 15A capacitor question
The CCH35 has a higher heater voltage for use in AC/DC receivers, 7v .2a. The ECH35 is for AC only receivers with a 6.3v .225a heater. The CCH35 will operate in AC receivers if everything is tip top but may fail to oscillate if conditions are bad such as damp coils reducing their 'Q'.
The ECH35 is the correct valve. John. |
8th Nov 2017, 9:56 am | #31 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Pye 15A capacitor question
ECH35 and CCH35 apart from the heater differences are electrically the same.
So far as I know the receiver was designed for the ECH35. EDIT: Post crossed. Lawrence. |
14th Nov 2017, 3:06 pm | #32 |
Hexode
Join Date: Nov 2003
Location: Ossett, West Yorkshire, UK.
Posts: 482
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Re: Pye 15A capacitor question
This is one of my favorite sets.
You need to be very careful with this test! With the set tuned to a station turn the set or the chassis upside down. If the volume increases then the dust cores in the IF transformers have broken away from the brass adjusters. It's a common fault. I have had some success repairing them with Araldite but getting the slug concentric is hard. I now replace the IF transformers with a different type and if you use some with the same IF frequency they only need a very small adjustment to realign them. Last edited by See_Mos; 14th Nov 2017 at 3:19 pm. |
14th Nov 2017, 3:17 pm | #33 |
Hexode
Join Date: Nov 2003
Location: Ossett, West Yorkshire, UK.
Posts: 482
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Re: Pye 15A capacitor question
The first one I swapped the IFT's on was the Pye 18A and the second a 15A, note the temporary Zaerix top cap!
I prefer the IFT's with side adjust cores rather than the top trimmer adjust but both worked. |
19th Nov 2017, 8:19 pm | #34 |
Tetrode
Join Date: Jan 2017
Location: Mansfield, Notts, UK.
Posts: 77
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Re: Pye 15A capacitor question
Many thanks See Mos. Will perform the test as suggested this week as soon as time allows.
Nick
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19th Nov 2017, 9:15 pm | #35 |
Heptode
Join Date: Jan 2016
Location: Nottinghamshire, UK.
Posts: 676
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Re: Pye 15A capacitor question
I dont know but am interested in the thread would it be possible pull up the core useing a magnet possibly one of the strong but cheap pen type? And would the magnet hold it until an adhesive dried?
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20th Nov 2017, 10:51 am | #36 |
Hexode
Join Date: Nov 2003
Location: Ossett, West Yorkshire, UK.
Posts: 482
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Re: Pye 15A capacitor question
By the way, for those of you who are thinking that it's a poor job, I did replace both IFT's in the 15A so that they matched
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20th Nov 2017, 11:01 am | #37 |
Banned
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
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Re: Pye 15A capacitor question
If the other core in the transformer will come out, a sliver of foam rubber or a light brass spring between the cores will hold them in position whilst it is realigned.
A terrible fudge but it stands a chance of working again. |