Golborne Vintage Radio

Should have done this years ago !   Its spring time and clearing up. 

Always use Silicon Rubber Insulated Wire from Phil Marrison who has a stall at BVWS Swap meets He will supply by post if you dont get to those.  ( Message me for his E-mail if you havent got it ).  Its easy strip and doesnt burn with the soldering iron.

Current offering is 0.5mm sq and 0.75 sq with current ratings of 3A and 4.5A.  I use the thin for general radio wiring and the the thicker for heaters, earth and HT.

I had the wire up until now just chucked in a box in a huge tangle.  It actually degrades it because getting a straight piece isnt easy and sharp kinks dont really come out.  So having bought some new stock I made the wire rack.

The key here is the beautiful NEW spools:
PLASTIC SPOOL PLASTIC BOBBIN ABS 100mm x 100mm x 63mm x 16mm, Plastic Bobbin | eBay

At a sensible price and low postage.

Note that I have put two wire colours ( resistor code   ) on each spool.  These come with two holes, top and bottom of each spool face, that pass 16 swg tinned copper with through nicely.   A short piece of this is bent through this, and turned over on the outside, to make a flat loop that holds the wound wire at start and end.  I used some 8mm threaded rod that I had as the spool supports but 15mm copper pipe would also work with a Jubilee Clip each end to fix it.

Thought possibly some Members might be interested

[attachment=21978]


Gary

Neat, 4.5A of HT must be something big

Well you wouldnt run the wire at its limit would you. The wire size could obviously be smaller but the size looks right in 30's chassis. It also helps to identify the HT stuff if checking a completely re-wired set up. I use the smaller size for reduced voltages feeding from the HT line or in cable forms.

Cant find a better wire for the sets I work on.

Gary

Just an example: this was a rust bucket and all metal work got re-plated.

That chassis looks better than new (agree about the wire size, got to look the part).

It has been said that I make the look too good but really I didnt see an option here:
[attachment=21981]
[attachment=21982]

And its such a beautiful and rare radio, even has LW, and I enjoyed doing it so much.  Been on a nostalgia trip looking at the pics and even had the radio playing.  Your comments triggered that Perdio  

thanks, Happy days  

Gary

Nice to see an RF stage too!!. Many of those "mantle style " sets lacked that facility.
I must say that IS a beautiful job !!!. 10 points.

Joe

"Nice to see an RF stage too!!. ..."  Thats why US radios sold well 'down under' Joe.  Distances could be large in America as also there.

Would need a chunky mantelpiece though:  it stands almost 2ft high and weighs quite a bit.

Thanks for the score of 10      

Gary

Looks like a table model to me, and very nice too!

Even many US battery models had an RF stage. But also the heptode and octode mixer-oscillator common even in US mains sets radiates more on the aerial than the traditional Hexode-Triode Mixer-Oscillator used in UK and most of rest of Europe. It's also why mains valve sets have a triode RF amp on the VHF tuner (or Triodised pentode) because otherwise in-band radiation of the LO-Mixer is a problem, the gain isn't significant. Battery valve sets with VHF (DC90, then triodised DF97, see https://www.radiomuseum.org/tubes/tube_dc90.html ) had very complex carefully adjusted baluns to minimise re-radiation and thus often had two whips or a loop. More common on Continental Europe, no USA models and only two portable & 1 table model in UK.

So while the RF stage for MW (LW not used for regular USA stations, only beacons and aeronautical) is common on USA mains and battery sets it might be as much for reducing Heptode/Octode mixer radiation as extra gain. In UK and rest of Europe usually only sets with SW had an RF stage, but most used Hexode-Triode Mixer Osc.

A few mains and battery sets used a separate triode oscillator (and if a heptode or octode used it was as a mixer only) but this was for stability and avoidance of a strong signal beside tuned weak signal FMing the oscillator rather than radiation concerns as such sets always had an RF stage.
See https://www.radiomuseum.org/r/hallicraft_s_72_s72.html which has 8 battery valves, RF stage, two IF amps, separate LO and BFO valves.

Typical Continental Europe battery valve AM/FM https://www.radiomuseum.org/r/philips_an...80_ab.html
The Ever Ready and Vidor AM/FM valve portable sets are untypical. The Ever Ready reflexes one RF valve as audio phase splitter for push pull and the Vidor uses FM 1st IF (DF97) as AM pentode mixer. The FM mixer/osc (DF97) is AM Local oscillator.
There may be a couple of European sets using dual conversion for FM. The DK96 is used on FM for 10.7 to 6.5MHz conversion, on many AM/FM battery sets the AM mixer/oscillator is off, though on some Philips models the DK96 grid is filtered and is the negative bias even on FM and Gram (so is kept on) for the push-pull output stage. It uses the DM70 as a triode phase splitter and power indicator rather than as tuning indication.
AFAIK all superhet AM/FM battery valve sets use the triodized DF97 (or early models the triode DC90) as additive mixer-osc with no RF stage, so can cause FM interference. Some mains sets use 2 x EF80, or ECF82 or ECC85, but all are actually an RF buffer and additive triode mixer-oscillator. Some late USA models used nuvistors for the VHF tuner, but they are just miniature valves.

[Edit there was one "novelty" single tube super-regen USA battery valve VHF model. No portables till transistors as FM was sold as HiFi, so only consoles from the start Band I before 1945, Band II from 1945. Germany had many AM channels taken by Allies, so FM started in 1949 and portable models almost as soon as DC90 was released. Ireland almost 1962 for FM Radio, but many received UK BBC FM from 1955)

I must admit, I dont think I have ever seen an american radio here. Then again, I doubt Ive seen any English ones either.
We did have lots of German sets though, due to migration after the war. Australia had umpteen dozen small radio manufacturers and most of my experience has been with those.
Some few had RF stages. As a kid I was given a few "dead " battery radios, but the cost of batteries prevented me ever getting any going.
There may have been long wave bands here once, but thats way before my time. FM started about 1975, but was experimental and I didnt see any. After all, most FM only goes round the block, and is pretty useless in Australia.
Ive never seen any FM radios, except the German ones, and I have never owned an FM receiver, but I am only 70. :-) All the FM sets I have been have been sand and made inJapan, although I was once asked to repair a Goodmans English FM tuner.

so my clip is from Wikipedia.

cut/paste :

During the 1980s, much of the band was still occupied by a few television transmitters,[10] but by the 1990s these had been reallocated to other bands, and are now closed, along with all other analog broadcast TV services, following the advent of digital television. As AM/FM portable and car radios displaced AM-only receivers, conversion to FM-stereo became progressively more attractive to broadcasters, and the swing to FM with its superior sound quality and immunity from interference, was under way. Many AM stations transferred to FM, with its lower costs, and many new services were opened. Today, as elsewhere in the developed world, most Australian broadcasting is on FM - although AM talk stations are still very popular and high-power AM transmitters, both national and commercial, are valued by travellers and country listeners, and in emergency situations.