Avometer model D from 1939 - UK Vintage Radio Repair and Restoration Discussion Forum

23rd Apr 2019, 12:43 pm

Today I received an Avo model D.

The movement was stuck due to the parcel received a big hit. Despite that I was able to correct the axe position that was out of the joints.

Now the Avo is working in all ranges.

The baquelite case is not original. I think the original one was made of aluminium with the battery cover at the back like model 4/5
I will appreciate if samebody could confirm that.

On the other hand, the front is from a model 40 but with the typical k1/k2 button of model D. early model?

Also the Q button is fixed with a screw, is not functional and it seems to be like that from origin. I can see at the back of the baquelite mould some holes that I assume are for the spikes and others parts for model 40.

The circuit is different to others model D I have seen.

Any idea about this model D??

Sinewave · 23rd Apr 2019, 4:38 pm

That's a Model 40, which the D was based on. Yours appears to have a D back and a 40 front.

Yours is possibly a replacement back, fitted in the 40s.

There were some early D's with battery compartments at the rear, but the rest (40s) were at the top like yours.

The Philpott · 23rd Apr 2019, 6:06 pm

No, it's most definitely a Model D.

There seems to have been an excess amount of Model 40 facia mouldings spare, and a lot of them were used to make the Model D. This is why you will occasionally see a Model D for sale which is thought by the seller to be a Model 40 based on the writing moulded on the front (a reasonable assumption!)

It all looks quite original to me. I can confirm that the Model D was produced with both aluminium and bakelite cases. I theorised that a stockpile of aluminium ones were set aside and used when production of the bakelite cases couldn't keep up with demand.

Those high voltage shunts look interesting, i haven't seen anything like them before.

The Q knob is always redundant on a Model D, usually just glued in. Many of them show plier marks where people have tried to rotate them without reading the instructions.

Dave

The Philpott · 23rd Apr 2019, 6:34 pm

I also notice it has an early one-piece scaleplate, without the AM Air Ministry mark at the top. Also looks like the 150v shunt is open circuit and has been bypassed- they usually are.

Dave

Sinewave · 23rd Apr 2019, 6:39 pm

I stand corrected.

Yes on closer inspection I can see the ranges are that of a D and not a 40. I never knew they used 40 fronts!

The Philpott · 23rd Apr 2019, 7:03 pm

They have done their best to confuse historians!

dave

23rd Apr 2019, 8:28 pm

Yes, it is a model D for sure, as i said and The Plipott notice, the circuit is quiet different to the others model D i have seen.

I am sure that the baquelite case is not original due to tha Avo only have 4 useful screws, two on the top and 2 on the bottom, the others are "close" by the case, that has the originals holes refill with some kind of plastic or rubber material, so only 4 screws to open it.
The instructions plate is original and attache under the rubber feet that are fixed by screws instead of rivets, Also the 2 rivets at the upper corner of the instructions plate are missing due to the case is not original. The battery cover is not original, is well hand made in soft plastic. It uses only one 1,5 volts battery as it should be.

As the instructions plate has "Douglas street" on it, i assume it is original and the the original case for that 1939 Avo should be baquelite, as aluminiun do not have that style of instructions plate.

Yes, there are 2 resistors instead of a shunt, and the scale plate has not the AM mark.

Any idea why it has a different circuit?

26th Apr 2019, 9:42 am

Is there any Avo 40/D baquelite case avaliable our there?

Sinewave · 27th Apr 2019, 11:24 am

Ahh, you know what I just noticed?

My 48A Admiralty pattern has a Model 40 front!

The Philpott · 27th Apr 2019, 2:50 pm

Post No.9- Yes, my Model 48A has the same legend, forgot to mention it!

As regards cases (or back-boxes as i refer to them) i found out quite quickly that in the event of a broken case (or corroded aluminium case) it's not always possible to do a straight swap with a better one- In the early days at least 3 different jigs were in use for making the holes for the casing screws, and you often find some or all of them won't line up.

Dave

23rd Apr 2019, 12:43 pm	#1
Guest Guest Posts: n/a	Avometer model D from 1939 Today I received an Avo model D. The movement was stuck due to the parcel received a big hit. Despite that I was able to correct the axe position that was out of the joints. Now the Avo is working in all ranges. The baquelite case is not original. I think the original one was made of aluminium with the battery cover at the back like model 4/5 I will appreciate if samebody could confirm that. On the other hand, the front is from a model 40 but with the typical k1/k2 button of model D. early model? Also the Q button is fixed with a screw, is not functional and it seems to be like that from origin. I can see at the back of the baquelite mould some holes that I assume are for the spikes and others parts for model 40. The circuit is different to others model D I have seen. Any idea about this model D?? Attached Thumbnails Last edited by Guest; 23rd Apr 2019 at 12:56 pm.

23rd Apr 2019, 4:38 pm	#2
Sinewave Octode Join Date: May 2016 Location: Oxfordshire/Bucks borders, UK. Posts: 1,604	Re: Avometer model D from 1939 That's a Model 40, which the D was based on. Yours appears to have a D back and a 40 front. Yours is possibly a replacement back, fitted in the 40s. There were some early D's with battery compartments at the rear, but the rest (40s) were at the top like yours. __________________ Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.

23rd Apr 2019, 6:06 pm	#3
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,107	Re: Avometer model D from 1939 No, it's most definitely a Model D. There seems to have been an excess amount of Model 40 facia mouldings spare, and a lot of them were used to make the Model D. This is why you will occasionally see a Model D for sale which is thought by the seller to be a Model 40 based on the writing moulded on the front (a reasonable assumption!) It all looks quite original to me. I can confirm that the Model D was produced with both aluminium and bakelite cases. I theorised that a stockpile of aluminium ones were set aside and used when production of the bakelite cases couldn't keep up with demand. Those high voltage shunts look interesting, i haven't seen anything like them before. The Q knob is always redundant on a Model D, usually just glued in. Many of them show plier marks where people have tried to rotate them without reading the instructions. Dave Last edited by The Philpott; 23rd Apr 2019 at 6:11 pm.

23rd Apr 2019, 6:34 pm	#4
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,107	Re: Avometer model D from 1939 I also notice it has an early one-piece scaleplate, without the AM Air Ministry mark at the top. Also looks like the 150v shunt is open circuit and has been bypassed- they usually are. Dave

23rd Apr 2019, 6:39 pm	#5
Sinewave Octode Join Date: May 2016 Location: Oxfordshire/Bucks borders, UK. Posts: 1,604	Re: Avometer model D from 1939 I stand corrected. Yes on closer inspection I can see the ranges are that of a D and not a 40. I never knew they used 40 fronts! __________________ Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.

23rd Apr 2019, 7:03 pm	#6
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,107	Re: Avometer model D from 1939 They have done their best to confuse historians! dave

23rd Apr 2019, 8:28 pm	#7
Guest Guest Posts: n/a	Re: Avometer model D from 1939 Yes, it is a model D for sure, as i said and The Plipott notice, the circuit is quiet different to the others model D i have seen. I am sure that the baquelite case is not original due to tha Avo only have 4 useful screws, two on the top and 2 on the bottom, the others are "close" by the case, that has the originals holes refill with some kind of plastic or rubber material, so only 4 screws to open it. The instructions plate is original and attache under the rubber feet that are fixed by screws instead of rivets, Also the 2 rivets at the upper corner of the instructions plate are missing due to the case is not original. The battery cover is not original, is well hand made in soft plastic. It uses only one 1,5 volts battery as it should be. As the instructions plate has "Douglas street" on it, i assume it is original and the the original case for that 1939 Avo should be baquelite, as aluminiun do not have that style of instructions plate. Yes, there are 2 resistors instead of a shunt, and the scale plate has not the AM mark. Any idea why it has a different circuit?

26th Apr 2019, 9:42 am	#8
Guest Guest Posts: n/a	Re: Avometer model D from 1939 Is there any Avo 40/D baquelite case avaliable our there?

27th Apr 2019, 11:24 am	#9
Sinewave Octode Join Date: May 2016 Location: Oxfordshire/Bucks borders, UK. Posts: 1,604	Re: Avometer model D from 1939 Ahh, you know what I just noticed? My 48A Admiralty pattern has a Model 40 front! __________________ Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.

27th Apr 2019, 2:50 pm	#10
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,107	Re: Avometer model D from 1939 Post No.9- Yes, my Model 48A has the same legend, forgot to mention it! As regards cases (or back-boxes as i refer to them) i found out quite quickly that in the event of a broken case (or corroded aluminium case) it's not always possible to do a straight swap with a better one- In the early days at least 3 different jigs were in use for making the holes for the casing screws, and you often find some or all of them won't line up. Dave