AVO all wave oscillator (Battery) - UK Vintage Radio Repair and Restoration Discussion Forum

kenny65 · 12th Aug 2014, 8:30 pm

Hello all.

My first post on this forum and I'm seeking help.

As I'm rapidly approaching a forced early retirement I'm finding more time to mess around with radios again.I am currently putting together some test gear and have acquired an AVO all wave oscillator.

Its the battery driven model. The 4.5 v LT battery shouldn't be a problem but the HT battery is I believe a 75v dry cell (Ever Ready 437)

My problem is I've never seen one and don't know what it should look like.

Any descriptions or indeed suggestions on multiples of commercially available batteries that would approximate the look would be appreciated.

Thanks in advance.

Kenny

Ed_Dinning · 12th Aug 2014, 9:16 pm

Hi Kenny, from memory the mains and battery units were very similar. The mains unit was fitted in a wooden box inside the instrument and made contact by brass tags.
Valves used would be different but I suspect had the same base connections.
So you have a choice, lots of PP3's, or make up a little mains unit for the batteries, or make up the correct mains unit and change the valves.

Ed

mark pirate · 12th Aug 2014, 9:24 pm

I have the mains powered version, it is connected to the power supply as Ed suggests. I take it there is a battery box in the bottom of your unit.
Let my know if you would like me to post some photos of the internals of mine, it may help if you want to convert it to run from the mains.

Mark

Phil G4SPZ · 12th Aug 2014, 10:00 pm

Hi Kenny and welcome to the Forum.

I too have the mains-powered model, but in your case as the battery-powered variant is less common I'd be inclined to make up a replica battery, and keep the convenience of having a totally portable signal generator as well as retaining the existing valves. There's also less of a shock risk if you ever have to do any fault-finding. The HT current will be very low, so a series string of eight Pound-shop PP3 batteries should last a long time. Similarly, three C or D cells in a holder should cater for the LT requirement.

You may be lucky and find a scanned image of the outer case of the original battery, but if appearance is of no concern, a simple box made from stout cardboard will suffice.

I'm attaching a copy of the manual in case you don't have one.

Phil

kenny65 · 13th Aug 2014, 10:53 am

Well thanks all for the very prompt replies.

I have just relieved an online retailer of a nice cheap box of pp3's and a couple of 4.5 v cycle lamp batteries.

If anyone has a sketch/photo or even description with rough dimensions of the 75v ht battery,please take a couple of mins to post.

My knowledge or experience of this older equipment is non existent,I did my training in the 80's. We did get valve theory but were told we would never see them in 5 yrs time.

Well here I am 30 odd years later proving that wrong.

Thanks again all.

12th Aug 2014, 8:30 pm	#1
kenny65 Retired Dormant Member Join Date: Aug 2014 Location: Lochgilphead, Argyll, Scotland. Posts: 2	AVO all wave oscillator (Battery) Hello all. My first post on this forum and I'm seeking help. As I'm rapidly approaching a forced early retirement I'm finding more time to mess around with radios again.I am currently putting together some test gear and have acquired an AVO all wave oscillator. Its the battery driven model. The 4.5 v LT battery shouldn't be a problem but the HT battery is I believe a 75v dry cell (Ever Ready 437) My problem is I've never seen one and don't know what it should look like. Any descriptions or indeed suggestions on multiples of commercially available batteries that would approximate the look would be appreciated. Thanks in advance. Kenny

12th Aug 2014, 9:16 pm	#2
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: AVO all wave oscillator (Battery) Hi Kenny, from memory the mains and battery units were very similar. The mains unit was fitted in a wooden box inside the instrument and made contact by brass tags. Valves used would be different but I suspect had the same base connections. So you have a choice, lots of PP3's, or make up a little mains unit for the batteries, or make up the correct mains unit and change the valves. Ed

12th Aug 2014, 9:24 pm	#3
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: AVO all wave oscillator (Battery) I have the mains powered version, it is connected to the power supply as Ed suggests. I take it there is a battery box in the bottom of your unit. Let my know if you would like me to post some photos of the internals of mine, it may help if you want to convert it to run from the mains. Mark

13th Aug 2014, 10:53 am	#5
kenny65 Retired Dormant Member Join Date: Aug 2014 Location: Lochgilphead, Argyll, Scotland. Posts: 2	Re: AVO all wave oscillator (Battery) Well thanks all for the very prompt replies. I have just relieved an online retailer of a nice cheap box of pp3's and a couple of 4.5 v cycle lamp batteries. If anyone has a sketch/photo or even description with rough dimensions of the 75v ht battery,please take a couple of mins to post. My knowledge or experience of this older equipment is non existent,I did my training in the 80's. We did get valve theory but were told we would never see them in 5 yrs time. Well here I am 30 odd years later proving that wrong. Thanks again all.