I've just picked up (remotely) a valve portable in moderate case condition, described as working, which will take a few days to reach me.

It's a Hotpoint, model Q75 MA R.

Haven't seen tech specs yet, but it seems to be a re-badged AWA chassis and body very similar to the AWA Radiola 5.

Any pointers to service docs would be appreciated.

Maven

Hi Maven,

I can't find reference to a Hotpoint Q75MAR anywhere. There is a P75MAR that's a 6 valve battery portable (AWA 653P). Circuit is on Keven chant's website;

http://www.kevinchant.com/model-numbers-601---700.html.

It's quite possible possible they did make a Q75MAR but circuits after 1955 are a bit sketchy.

The Hotpoint equivalent of the AWA Radiola 5 was the P65ME. This was a badge engineered AWA 565MA with cosmetic differences but identical chassis manufactured by AWA. The circuit for this is on Kevin Chant's website;

http://www.kevinchant.com/model-numbers-501---600.html.

The four valve version of this was the P64ME (AWA 449MA) and P64MEX (AWA 467MA) the only difference being the P64MEX had an internal ferrite core aerial.

You might have to wait for it to turn up so you can check the valve lineup.

Cheers,

Warren

I would sit on the fingers, It's probably a badge engineering job & will share a circuit with an AGE, AWA, or something else they built.

Marc

Thanks for that. The AWA 653P looks most like it - it is a six-valve set. Good 14-page docs thanks to Kevin Chant.

So now I just close my eyes, open my mouth, and see what the fairies will bring me.

I received this Hotpoint and it is indeed identical chassis to AWA 653P. Best of all, the chassis was generally in good condition, all voltages checked out OK, and "crackle" issues flagged by the seller are no more than a loose 3-pin socket connecting the internal loop antenna and dirt in the volume pot, solved with WD40.

Body was another story, and I am embarking on major restoration of the case. It looks like this radio spent a good part of its life as a farmer's or tradesman's companion, resulting in paint and oil stains to the exterior and a considerable deposit of clay dust inside the speaker cone! Also some evidence speaker cone has been a bit wet at some point, though it still functions reasonably. It's marked as 6PT 2107A VC 3ohm. The bottom half of the cone, the cork mounting has detached from the metal frame, so the cone has pulled back a few mm to leave a squarish bottom half - probably water damage loosed the glue? I'll try to epoxy that back to full round shape, which means stretching the cone more tightly while gluing. Fingers crossed.

A couple of case cracks epoxied, and I have patched a missing corner piece using polyfilla over a reinforcement made by super-gluing a piece of nylon flyscreen to form the inside of the rounded corner. If polyfilla turns out to be too weak, I'll move up to light aluminium sheet (as used in damp-course flashing) covered by automotive panel filler. I will be re-spraying the whole body.

The tuning dial window original perspex is discoloured and full of spider-lines like a smashed laminated windscreen. I got some 1mm clear polycarbonate sheeting to replace it. It has to include a 90degree curve at the top, which the light gauge transparent sheet can manage without heat-forming.

When the case is done, I aim to build a battery replacement that uses a solid-state circuit to bump 6v or 9v up to the required 90v B+. AC operation is no problem - using the same old-style appliance flex that was used on Hotpoint's more familiar products such as electric jugs and portable cooktops. That plug is non-polarised but fully earthed, and the power supply uses a transformer, so I know I'm not dealing with a "hot chassis" situation.

Knobs also need some epoxy reinforcement or reconstruction.

One question for AWA experts - the rotary power selector switch is marked (clockwise) ACTIVATE/AC/OFF/SAVE. What should I expect to see on ACTIVATE and SAVE positions? The chassis currently powers up on both ACTIVATE and AC.

Maven

I dont recall the exact teminology (differs between manufacturers) but a lot of late 40's on portables had a switch position to put a trickle charge back into the battery.
Dont know how effective it was re charging carbon batteries, maybe just a sales gimmick!

An identical radio has been listed for auction by "georgeandmargaret" (maybe a site member here?) as AWA RADIOLA 6 MODEL 679P MADE IN 1956 - a close look at the auction photos shows every detail including the case grille is the same as my Hotpoint, bar the brand and colour of handle - plus the advertised items case is in much better condition.

None of the sites I have checked have docs for AWA Radiola 679P - the closest I found is the 653P, so perhaps the changes were only cosmetic and chassis/circuit are the same. If anyone knows where 679P service docs might be found, I would like to know.

Still working on case restoration and will post a photo when completed. Paint seems to take a long time to dry on plastic.

Maven

[For the record - the AORSM and lists derived from it end at 1955. The Hotpoint Q75 MA R and the Radiola 679P are the 1956 models of the series that are based on the 1954 AWA 653 chassis, with only minor cosmetic updates to the plastic front case. Hotpoint ceased selling rebadged AWA radios in 1956, so this is the probably the last model that they sold.]

"georgeandmargaret" (maybe a site member here?)

Yes, see:

http://vintage-radio.com.au/default.asp?f=1&th=582#3461

I confirmed the identity of my Hotpoint by reference to a great full-page advertisement in Womens' Weekly in 1956, illustrating all the Hotpoint models, which I believe were in each case rebadged AWAs. The Q75 MA R turns out to be the "Hotpoint 6", a clone of the Radiola 6. I've posted separately in the "Cabinet Repairs" section about the extensive plastic case restoration.

The Trove link is here:

http://trove.nla.gov.au/ndp/del/page/5341269?zoomLevel=1&searchTerm=Hotpoint%20Radio&searchLimits=l-category=Advertising|||l-illustrated=y|||l-title=112|||l-australian=y.

The advertising theme is "cricket".

The chassis took more work than I first thought. The volume pot was scratchy, so I started to pull it out for inspection or replacement. Immediately I touched any of the black tar-paper caps, they fell to bits even though they had been working up to that point. Totally brittle and melted to goo if a soldering iron got too close. So I got a full set of metal and electro replacements from Just Radios. For the time being, I've just replaced the papers (wax and tar types) and the electros will be held in reserve.

Maven

What are you referring to as metals?

My experience with the AWA is that the Mud types like that are notorious for snapping and I have seen some of the caramel coloured polyesters of the 70's doing the same.

You replace all of the muds & all of the electrolytics. The metal type are very likely the MIca ones. I have never seen one of them fail in an AWA built set. Make sure that you check resistors, I normally do that as I change the caps.

I saw some on the plate bypass of some output tubes of a late thirties set recently, and that position is hard on caps. I tested them at 500V & left them there along with all of the ones of the same construction.

Marc

To be more precise, I've replaced 9 wax and black "mud" paper caps up to 0.1μF with tubular axial metal film caps.

Of the 4 electros in the 653P circuit, the largest is in the pan but the other three are in one Ducon can above the chassis. If I was doing this for somebody else I would swap the lot, but as this radio isn't going anywhere and there is no sign yet of problems with the electros, I'm keeping those for another day.

Maven