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-   -   HAC SW Single Valve (https://www.vintage-radio.net/forum/showthread.php?t=32349)

Mr. Bacchus 16th Sep 2008 3:20 pm

HAC SW Single Valve
 
Firstly, apologies for my username. The leaflet is in front of my so hence my 'inspiration'.

I have a seemingly old HAC manufactured by Arthur Bacchus when he was working out of Hartington Road, SW 8 and was wondering if anybody has any more information on it. All I seem to have learnt to date is that HAC is an acronym for 'Hear All Continents'.

Cheers,
Phil

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Station X 16th Sep 2008 3:45 pm

Re: HAC SW Single Valve
 
Have you looked here:-

http://wftw.nl/hac/hac.html ?

Mr. Bacchus 16th Sep 2008 3:53 pm

Re: HAC SW Single Valve
 
Yes! I've e-mailed Maurice and am awaiting a reply.

With reference to your 'tag', I've just finished a contract not far from you (Huntingdon) and found out my gas iron was more than hot enough when I put my palm on it!

I'm an automotive installer working in the field.

Cheers Graham.

Station X 17th Sep 2008 10:59 am

Re: HAC SW Single Valve
 
Quote:

Yes! I've e-mailed Maurice and am awaiting a reply.
I think you mean Louis. I'm sure he'd appreciate a scan of the HAC booklet in your picture. It may be tatty and torn, but there are forum members who can fix that using photoshop or similar software.

Herald1360 17th Sep 2008 12:51 pm

Re: HAC SW Single Valve
 
??? curious about the set in the pictures- the leaflet refers to 1 valve, but the set clearly has 2.

Also, ISTR that HAC receivers were much more recent than the style of your set (they were still advertised in the 60's and 70's), but maybe they've been around longer than my memory and just been modernised over the years. The one valver kits I recall used open chassis and front panel construction rather than mahogany box. In fact the octal valves are somewhat later than the style of enclosure so maybe your set is a home brew interpretation using junk box bits rather than an actual HAC.

Whatever yours is, it looks like an interesting and hopefully rewarding challenge to get working.

Chris

Station X 17th Sep 2008 1:24 pm

Re: HAC SW Single Valve
 
HACs date back to at least 1938 and apart from the later use of Denco coils the design changed little. It looks like Phil has a nice set of coils there anyway.

Mr. Bacchus 17th Sep 2008 1:51 pm

Re: HAC SW Single Valve
 
Quote:

The one valver kits I recall used open chassis and front panel construction rather than mahogany box.
Yes, in the course of my research I have found plenty of pics showing the '3-sided' box along with a Paxolin tag strip!

Clearly there are TWO valves! I am so thick! The one on the left is a Marconi HL2 which appears to be coated in graphite? The other has no identifying marks but has a 5 pin base with the pins making an arrow shape.



Louis/Maurice.

My mistake, I e-mailed Maurice Woodhead. Not Louis. The quick pic of the leaflet was really just that. I would be happy to send a decent scan to anybody who might find it interesting.

There are a number of coils (visible in the lid) which fit into a base to the left. I am assuming these are to change the receiving frequency along the SW band.

Let's imagine for a moment that I am considering 'lighting the boiler'! From what I remember from my youth, our family radio had a 50vdc dry cell Ever Ready so I'm guessing (probably wrongly) that this is about right to 'light' the tubes but I will start safely off at a sociable 24v and ramp it up. The aerial terminal is on the right hand side and I'm guessing (again) that my ground is off the -ve side of the PSU.

If you see reports of a mushroom cloud near Edinburgh then you'll know what it is!

Thanks for the replies.

Mr. Bacchus 17th Sep 2008 2:04 pm

Re: HAC SW Single Valve
 
Chris,

You've got me thinking now. I suspect your guess at a 'home built' set might be right. The leaflet seems to show only one tuning cap. There is a second (trimmer?) on the right hand side. The circuit diagram also has just the one tube.

JHGibson 17th Sep 2008 3:58 pm

Re: HAC SW Single Valve
 
Be very careful to connect the batteries to the right wires. You will need a 2 volt accummulator for the filaments and a high tension battery for the HT+. 50 volts would be OK for the HT. There might be a requirement for a third battery to provide grid bias for the output valve. I hope your user manual clearly indicates which wires are which! and what batteries are required. Connecting the HT battery to the filaments would destroy the valves.
Polarity of the batteries is also important. If you reversed the wires to the HT battery, the radio would not work. Ditto the bias battery.
John.

Mr. Bacchus 17th Sep 2008 5:08 pm

Re: HAC SW Single Valve
 
Hi John,

The circuit diagram shows both HT & LT which is pretty much what you summised in regards to seperate voltages. High voltage to light the tube with a nominal voltage passing through? This much I am starting to remember! However, I am inclined to go towards Chris's guess as in this is a 'shed' built job but using the HAC design as a template.

I promise not to apply voltage until you are all clear!

wireful3 17th Sep 2008 5:20 pm

Re: HAC SW Single Valve
 
The high voltage is definitely NOT to light the tube. This is the purpose of the 2 volt LT battery.

Mr. Bacchus 17th Sep 2008 7:38 pm

Re: HAC SW Single Valve
 
Hi John,

Thanks for the 'heads up', Edinburgh is safe for now. Thanks for all the help but I'm still a little scared! I will post a detailed schematic of the 'motherboard' in the hope that I can be pointed in the right direction.

Thanks again for all the kind and patient replies.

PJL 17th Sep 2008 8:11 pm

Re: HAC SW Single Valve
 
Looks like it is a hacked about Gecophone Crystal set box...

Mr. Bacchus 17th Sep 2008 9:30 pm

Re: HAC SW Single Valve
 
Hi JPL,

Yes, on closer inspection the 'motherboard' is evidently homemade. The tuning dial is also above the line of the box which also adds weight to your suggestion.

I think the one thing that might put people off track is my reference to the leaflet I found in the box. It is obvious now (even to me) that it is not directly associated with the set although it may have been an inspiration to the builder. He may even have left it there to say 'look, I can do better'.

Again, thank you for the kind and patient replies.

Andy Day 18th Sep 2008 8:33 pm

Re: HAC SW Single Valve
 
Hi there.

The diagram you show is for a model C I see from the front page, I made one of these in the early 60's. It was an ally chassis about 6 by 4 with a similar size front panel. I seem to remember it had a bandset and bandspread tuning cap, HL2 triode, I guess it must have been 2v LT and 60 to 90v HT but I can't remember how this was acheived.

In spite of a 100ft aerial and a big iron rod bashed into the ground - I think it was the sawn out sideframe of an old bedstead, it was fairly useless at receiving much. Not as good as my excellent Selena B210 anyway, but that is no surprise!

No idea about the set you show, unless it's a homebuilt one. Looks interesting though - well worth some attention.


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