UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Test Gear and Workshop Equipment

Notices

Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders.

Closed Thread
 
Thread Tools
Old 8th Mar 2019, 11:01 am   #81
Superscope
Hexode
 
Join Date: May 2017
Location: St Austell, Cornwall, UK.
Posts: 340
Default Re: Avo 36 range restoration

Aitor,

Just noticed a mistake in my previous Post.
Just in case you didn't spot it.

It should have said:

"To avoid delay in despatch. it is requested that re -
mittances accompany all orders for fuses and cells."

So "requested", and NOT as I incorrectly typed last time "request"

I also note, that AVO seem to have spelled "despatch" incorrectly!
The correct spelling is "dispatch" however, on my Label, AVO definately
didn't use an i.
The Printing was not of the same Quality as the Meter.
The printing was originally of Poor Quality and the Label appears to have
been Hand Cut to size with Scissors.


Ian
Superscope is online now  
Old 8th Mar 2019, 12:00 pm   #82
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

Thanks, i corrected that!!

I finished it and printed in a self-adhesive paper, i cutted it badly due to the original is like that, also i glued it on the reverse of the battery cover in the same way as original, i mean no perfect horizontal. That is only for test, i must polish a little bit the battery cover. Originally is only painted by the outside.

The type of the letter is quite the same, the size is a little bit smaller, but i think it is not such important. Perhaps the capital letters like "FUSE" should be little bit bigger, but for me is OK. The bad speeling on "despatch" was respected as the lack of capitals letters after a full stop. I printed it on red because in my Avo 34 ranges there was half label left of this colour.

The original size is

3,2 Cm x 6 Cm

Attached there is the JPG file if anybody is interested.

Special attention was taken on the position of the letters respect the letters immediately over, also on the spaces between them, etc.

I hope it is useful for the Avo collectors community!!!
Attached Thumbnails
Click image for larger version

Name:	Avo %22Fuse%22 label for 34 and 36 range by Aitor Eneko.jpg
Views:	60
Size:	81.5 KB
ID:	179583   Click image for larger version

Name:	IMG_7683.jpg
Views:	64
Size:	138.2 KB
ID:	179585  

Last edited by Aitor Eneko; 8th Mar 2019 at 12:24 pm.
Aitor Eneko is offline  
Old 8th Mar 2019, 1:42 pm   #83
AndyGilham
Pentode
 
Join Date: Oct 2016
Location: Dover, Kent, UK.
Posts: 200
Default Re: Avo 36 range restoration

Not incorrect, both 'Dispatch' and 'Despatch' are acceptable spellings. However, Despatch was the more common spelling used in the early/mid 1900's

Andy
AndyGilham is offline  
Old 8th Mar 2019, 2:50 pm   #84
Superscope
Hexode
 
Join Date: May 2017
Location: St Austell, Cornwall, UK.
Posts: 340
Default Re: Avo 36 range restoration

Hi Andy,

Yes, just looked it up and you are absolutely correct!

Both spellings are apparently acceptable English and
as you say, despatch was more common in the Past.

I should have questioned the Microsoft Spell Check to start with,
knowing it doesn't like British English much, preferring instead some
strange dialect called American English, what ever that is!


Ian
Superscope is online now  
Old 8th Mar 2019, 9:04 pm   #85
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

Any opinion about the label?
Aitor Eneko is offline  
Old 10th Mar 2019, 12:45 pm   #86
AndyGilham
Pentode
 
Join Date: Oct 2016
Location: Dover, Kent, UK.
Posts: 200
Default Re: Avo 36 range restoration

It's certainly a label Aitor!! I'm not a fan of making reproduction of parts. I have just acquired a 1895 Evershed and Vignoles 120V generator and the label in not great, but I certainly don't want to replace it. I think it loses its authenticity. Just my opinion though..... You have done a decent job with it.

Andy
AndyGilham is offline  
Old 10th Mar 2019, 1:45 pm   #87
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

It is for the 36 range Avo, that the whole battery cover was missing, until I found an original one.

I think same way as you. On my 34 range, I will conserve part of the original label that survived
Aitor Eneko is offline  
Old 10th Mar 2019, 3:17 pm   #88
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

I mean until i find an original one, better with the label.
Aitor Eneko is offline  
Old 23rd Aug 2019, 1:40 pm   #89
Superscope
Hexode
 
Join Date: May 2017
Location: St Austell, Cornwall, UK.
Posts: 340
Default Re: Avo 36 range restoration

Finally!

I have finished the 36 Range Restoration.

The following were the faults found when I received it:



Heavily flaking Scaleplate.
Case Rim badly Bent Burred and chipped.
Pointer badly Bent and Twisted.
Screws missing all round.
Rubber Seal missing and hence Panel wedged into Case. Screwdriver had clearly been used previously in an attempted to get the Panel out.

P Knob totally seized in Panel

Large Resistance Board Cut off, refitted wrong way round and not connected.
4.9K, 57.3K & 122.7K all O/C
Missing Board mounting Spacers
Missing Mounting Screw x 1

Small Resistance Board
96Ohm, 10.5K & 750Ohm all O/C

Resistance Range Board
111Ohm Broken connection

Shunt Board
0.2Ohm Broken Connection

Fuse Bridged with Wire ( 0O )

AC Rectifier Leaky




I won't bore you all with all the repairs details, but some items of note are the reproduced Scaleplate,
courtesy of Aitor's friend Carlos who very kindly edited my Scanned Copy for me.
How he did it, I have no idea! He has reproduced the missing parts of the Scale incredibly well.

The result is really quite good and retains the Meters accuracy.
Printed on High Quality Photo Paper using an HP Photo Printer

You wouldn't know it is a reproduction without looking very closely.
The only thing that really gives it away, is my not 100% perfect cutting out of the Mirror Arc!


For the missing Terminal, I machined a new Screw section from a piece of Brass Rod, and took a Mould from the surviving Terminal Knob.

I Cast the New Knob over the New Screw Section using a Two part Resin + the Colour.

The Cast turned out very well. Only thing I can improve on next time is alignment of the Knob and Screw Thread,
but it looks Ok and this was my first attempted at reproducing an AVO part.

Made some New Board Spacers from Resin, reassembled and set about checking the Calibration!


The AC Ranges were all around 15% out of Spec, which turned out to be a Leaky Rectifier.

I took the Rectifier out of Circuit but left it in place so it all still looks original.
I experimented with different Diodes I had lying around, and was surprised to find that IN4148 Signal Diodes worked the best.
They will be underwhelmed with the 5mA requirement.
I formed Four of these into a Bridge Rectifier and hid them underneath. Big advantage of 4148's is they are very small.



It is now 99% in Specification, Technically, not quite 100% as the DC accuracy goes a little over 1% in some places.
AC is totally within the 2.25% Spec and I was amazed at how good the Resistance Measurements were! Easily with 5%.

Not bad for an 82 Year old AVO which will live to Work another few Years!


Ian
Attached Thumbnails
Click image for larger version

Name:	As received^.jpg
Views:	65
Size:	44.1 KB
ID:	188774   Click image for larger version

Name:	After Restoration^.jpg
Views:	68
Size:	107.6 KB
ID:	188775   Click image for larger version

Name:	As received Inside^.jpg
Views:	67
Size:	83.5 KB
ID:	188776   Click image for larger version

Name:	After Restoration Inside.jpg
Views:	69
Size:	91.7 KB
ID:	188777   Click image for larger version

Name:	Terminal Screw^.jpg
Views:	65
Size:	89.1 KB
ID:	188778  

Superscope is online now  
Old 23rd Aug 2019, 2:46 pm   #90
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

guauu!! it is a fantastic job!!! awesome!!

99% accuracy is much better than expected.

You should be very happy with your 36 range AVO.
Aitor Eneko is offline  
Old 23rd Aug 2019, 3:51 pm   #91
Sinewave
Octode
 
Sinewave's Avatar
 
Join Date: May 2016
Location: Oxfordshire/Bucks borders, UK.
Posts: 1,155
Default Re: Avo 36 range restoration

Fantastic Ian.

I have two of these I've yet to do anything with, though so far as I can tell one of them appears to be working.
__________________
Avometer, vintage Fluke and Marconi collector.

At 144-146.00Mhz, keeping one wavelength apart.
Sinewave is offline  
Old 23rd Aug 2019, 8:48 pm   #92
The Philpott
Nonode
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 2,213
Default Re: Avo 36 range restoration

Smarter than my Model 4! You probably just need a new leather strap now..
(I am too apprehensive to use any old straps that have signs of distress)

Dave
The Philpott is online now  
Old 26th Aug 2019, 10:45 am   #93
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

My easy solution for the battery in Avo model 4 and 5
Attached Thumbnails
Click image for larger version

Name:	E4BE5C14-B59B-4E2C-B819-A8D5F46C405D.jpg
Views:	61
Size:	86.9 KB
ID:	188932   Click image for larger version

Name:	E5F4B0FF-E512-4780-A1CA-71CA5217517C.jpg
Views:	56
Size:	66.8 KB
ID:	188933  
Aitor Eneko is offline  
Old 26th Aug 2019, 11:23 am   #94
The Philpott
Nonode
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 2,213
Default Re: Avo 36 range restoration

..That's very similar to how i have changed the battery compartment. You just have to remember to position the holder so that it's sides can flex when the cell is put in.
Dave
The Philpott is online now  
Old 28th Aug 2019, 5:43 pm   #95
Superscope
Hexode
 
Join Date: May 2017
Location: St Austell, Cornwall, UK.
Posts: 340
Default Re: Avo 36 range restoration

I think I would still prefer a slightly less Smart Model 4 though Dave!
That's a rare Beast.

This 36 Range actually still has it's original strap and it's in good enough
condition to use as is. I have carried the Meter with it.

I did give the Strap a dose of Leather nourishing compound and a Brush up
with Black Shoe Polish though.




Now more importantly, has anybody got an intact Fuse found on the early
Meters?

Mine is currently wound with Manganin Wire to give 4 Ohms, but obviously
won't function as a Fuse like that. I just wanted to get the Meter working for the moment.

Would be interested to see any photo's of how the original should look if anybody has any?

I have never seen the Value mentioned anywhere, but I assume the Fuse would have
been around 100mA.
I have based this on the Fuses I can find today, which, when they go lower than 100mA
the resistance goes above 4 Ohms.

It was only during the restoration of this 36 Range that it finally dawned on me why the Fuse had a 4 Ohm resistance!
Attached Thumbnails
Click image for larger version

Name:	P1070503.jpg
Views:	32
Size:	84.0 KB
ID:	189053  
Superscope is online now  
Old 28th Aug 2019, 9:33 pm   #96
The Philpott
Nonode
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 2,213
Default Re: Avo 36 range restoration

...My Model 4 fuse was blown as well, sorry!
(I did get one or two intact fuses for the Type E 'AM' Avominor)

Dave
The Philpott is online now  
Old 28th Aug 2019, 9:41 pm   #97
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

My model 4 fuse
Attached Thumbnails
Click image for larger version

Name:	image.jpg
Views:	50
Size:	68.7 KB
ID:	189069  
Aitor Eneko is offline  
Old 28th Aug 2019, 10:19 pm   #98
The Philpott
Nonode
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 2,213
Default Re: Avo 36 range restoration

There is possibly a second screw hiding under that blob of solder.
The Philpott is online now  
Old 29th Aug 2019, 8:46 am   #99
Superscope
Hexode
 
Join Date: May 2017
Location: St Austell, Cornwall, UK.
Posts: 340
Default Re: Avo 36 range restoration

Aitor,

Your Photo deepens the mystery a bit!

I think your Fuse has been repaired in the past, so it is
difficult to tell what is definitely original, but the Mini Bobbin would make sense.

The Solder Blob is covering what would have been a small Screw.
I'm guessing the Screw was lost during a repair and Soldered or maybe AVO
decided this type of repair was acceptable for speed.
AVO sold new Fuses or repaired Blown ones at a slightly cheaper cost.

On the Fuse from my 36 Range, I had no Bobbin at all, just a Wire Link which somebody,
had obviously done during a repair attempt.
But there was evidence of a very Thin Brass coating on the Plastic Substrate which I measured at around 90 Ohms between the Fuse Terminals.

I thought that maybe this was part of the original Fuse System which had gone High Resistance.

I was hoping to see something similar on any Photo's Members might have, or any recollection of such.

The Wound Bobbin like yours does make more sense though.
So was the Bobbin original or an accepted repair method, or both I wonder?


Ian
Superscope is online now  
Old 29th Aug 2019, 8:59 am   #100
Aitor Eneko
Heptode
 
Aitor Eneko's Avatar
 
Join Date: Dec 2014
Location: Gran Canaria, Canary Islands, Spain
Posts: 531
Default Re: Avo 36 range restoration

Another one
Attached Thumbnails
Click image for larger version

Name:	B7048EC7-C018-45A1-BD9D-A2E5DA824E0C.jpg
Views:	40
Size:	68.2 KB
ID:	189072   Click image for larger version

Name:	092CB2F2-3153-4D7B-AB92-511C26C71143.jpg
Views:	34
Size:	82.9 KB
ID:	189073  
Aitor Eneko is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 10:40 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Copyright ©2002 - 2020, Paul Stenning.