Vintage 'Hikers' 1 & 2 radio designs.

[David G4EBT]

From the age of 13 back in 1952 when I had a newspaper round, I used to look forward to reading Hobbies Weekly, before I posted it through the recipients' letter boxes, which piqued my interest in crystal sets and 1-valve sets, as often as not from the pen of F.G. Rayer, but the cost of the parts and batteries extended beyond pocket money. (For a 6 day morning and evening newspaper round plus Sunday mornings, the princely sum of 5 shillings a week, [about £6.00 today], didn't stretch far!).

When I started work in 1954, I was able to get together the parts needed, but had variable success, which - looking back, was most likely due to coil winding. I had more success with some of the kits in the PW ads of the era, such as the 'Acorn 2-valver'.

Fast forward to the late 90s, I came across a now defunct New Zealand website 'www.oldradios.co.nz' with lots of reprints of articles on the 'Hikers' radios' which spanned the years from 1936 through to 1952. Some of the articles were from a a series of Annuals called 'The Lamphouse Annuals'.

Feeling nostalgic, in 1999 I got all the bits together to build a 'Hikers' Two' including two 1Q5T octal battery valves with 1.2V 0.1A filaments. As is so often the case, other things took over, so it never got built, and probably never will, but many have been built over the years, the world over. (That there are now so few short-wave and medium wave stations still broadcasting does rather dampen the enthusiasm, though not the interest in such simple designs).

Luckily, Mike Peebles who lived in Vancouver and was noted in Crystal Set Society, scanned and saved those articles for others to enjoy. To quote Mike: 'These scans were from a now defunct website in New Zealand. They were saved so the art of the Hiker's radio would be preserved. Download the scans and build your own version of the Hiker's'.

Sadly, Mike passed away in 2022, but at least for now, his website is still functioning.

Mike Peebles webpage:

http://www.peeblesoriginals.com/projects/hikers-radio.php

Mike’s scanned articles on his ‘’Hikers’ page:

https://www.peeblesoriginals.com/projects/hikers-radio.php

Radios that Mike Built:

https://www.peeblesoriginals.com/gallery/index.php

I've attach a copy of a typical Hobbies Weekly article, a circuit of a 'Hikers two' and a 'Hikers 1' reprint.

Other links which might be of interest:

The late Peter Lankshear:

Electronics Australia EA Unidyne, November 1983
EA The Hikers – "My first radio" by the late Peter Lankshear - Oct 1989:

https://nzvrs.com/wp-content/uploads/2018/11/the-hikers-my-first-radio.pdf

"The Unidyne - Popular Wireless' Damp Squid" BWS Bulletin April 1995:

https://www.bvws.org.uk/publications/bulletins/pdf/BVWS_Bulletin_20_2.pdf

"Unidyne Revisited" BVWS Bulletin June 1977:

https://www.bvws.org.uk/publications/bulletins/pdf/BVWS_Bulletin_02_1.pdf

Hope someone else might have as much enjoyment as I do from reading the articles.

[vinrads]

Hi David ,thank you for a very interesting post ,it has renewed my interest in building these little projects I know some people will say there is nothing on am these days, but here in Derbyshire I can always find a few stations like radio Derby, Five live to name a few, I remember Chas Miller doing an experiment with different coil formers, he came to the conclusion that glass was the best ,of course you have to find the correct dia for your needs , time to dig the box of 1920's bits out and get building. Mick.

[VT FUSE]

I would have found that article interesting, I think the famous Philips use of glass formers in the Superinductance involved a lot of science regarding the type of glass to use, a lot of glass types yielded low Q coils.

Years back when I wanted large bore thin wall formers,it was found impossible to find Polystyrene so I decided to try paint roller tubes, first I pulled the nap off some rollers and then mounted an expanding type roller carrier int a lathe and sanded off the glue remnants. The plain tube was identified by an industrial chemist as Polyester and allowed for very high efficiency coils to be wound.

I am sure that David would build a very impressive 2 valve receiver, doubtless the carpentry skills he has would give an amazing result.

British subs for the 1Q5/1C5 valves would be DL33/35/36 which only vary by different filament Voltage and also run well at 18V HT.

Mike.

[G6Tanuki]

I remember a 1930s 14/28MHz radio design that used test-tubes as glass formers for a receiver, and the matching transmitter had PA coils wound on wine bottles!

[Terry_VK5TM]

There's a collection of Lamphouse catalogues (with the circuits) here

https://www.worldradiohistory.com/New_Zealand_Miscellaneous.htm

[David G4EBT]

Thanks for the link to the Lamphouse Annuals Terry.

I hadn't realised just how comprehensive the annuals were or that they were really annual catalogues of the 'The Electric Lamphouse Ltd' who supplied equipment, electrical components, kits and appliances. The full annuals make very interesting reading - to me at any rate.

(One aspect of the 'Hikers' circuits is that none of the articles mention the frequency coverage of the coils).

[M0SOE_Bruce]

Originally Posted by David G4EBT

Fast forward to the late 90s, I came across a now defunct New Zealand website 'www.oldradios.co.nz' with lots of reprints of articles on the 'Hikers' radios' which spanned the years from 1936 through to 1952. Some of the articles were from a a series of Annuals called 'The Lamphouse Annuals'.

Hope someone else might have as much enjoyment as I do from reading the articles.

The original website (oldradios.co.nz/hikers/index.htm) is still available on the Internet Archive's Wayback Machine. Most of the info is still there and lots more.

[David G4EBT]

Thanks for reading the thread and for the info Bruce.

On the Wayback Machine I get the orginal 'oldradios.co.nz homepage up, but if I click on any items whether it's 'receivers, 'photo albums' or 'plans' etc. I get: 'page does not exist' or: 'Hmm the Wayback Machine has not archived that url'.

Maybe I've not found the 'open sesame key'?

https://web.archive.org/web/20250528220140/https://www.oldradios.co.nz/

[M0SOE_Bruce]

Interesting. It seems to work for me. I can access various links on the home page. Here is the link to xtal sets. I just had a good look there. Some of the project links were not saved.

https://web.archive.org/web/20110207015836/http://oldradios.co.nz/projects/xtalsets/index.htm

Boatanchor and xtal set photos are there.
I just noticed that the links I used were HTTP without the WWW.

Bruce

[David G4EBT]

Originally Posted by M0SOE_Bruce

Interesting. It seems to work for me. I can access various links on the home page. Here is the link to xtal sets. I just had a good look there. Some of the project links were not saved.

https://web.archive.org/web/20110207015836/http://oldradios.co.nz/projects/xtalsets/index.htm

Boatanchor and xtal set photos are there.
I just noticed that the links I used were HTTP without the WWW.

Bruce

Thanks for looking further into this Bruce.

Still no success for me, but in fact all the 'Hikers' articles at in the Lamphouse Annuals, which I hadn't known were archived at 'worldradiohistory'. The only extra stuff on oldradios.co.nz was a few examples of Hikers which had been constructed.

I have all the bits to build a Hiker's Two should the mood take me.

Here is the result of my attempts at the Wayback Machine

Clicked on this URL:

ftp://oldradios.co.nz/projects/buildamoderncrystalset/

Came back with:

Hrm.
The Wayback Machine has not archived that URL.
This page is unavailable for archiving. The server returned code:
because server does not respond
Click here to search for all archived pages under ftp://oldradios.co.nz/projects/buildamoderncrystalset/.

Clicked on that link which brought up:

‘No URL has been captured for this URL prefix’.

[Terry_VK5TM]

Edited.

Some ftp sites are not archived and it looks like that one isn't.

[David G4EBT]

Thanks Terry.

I've redrawn the scanned image of the circuit of the 'Hiker's Two' from 1951 Lamphouse Annual to make it clearer, which I've attached.

It calls for a 3:1 inter-valve transformer and I have a square shaped vintage 'Lissen' brand one, which in the pitch on the underside is stamped '4:1' which would no doubt suffice. I know that the DC resistance of a transformer isn't the same as it's impedance, but one side measures 1.3 K Ohms, and the other measures 13.5k Ohms. Hence if '4:1' means the turns ratio rather than impedance, (as I suspect it does), then the DC resistance is 10:1 - not 4:1.

I have another (circular) Lissen inter-valve transformer, in which the primary resistance is 600 Ohms and the secondary is 2,400 Ohms. That too is marked 4:1, which makes more sense and further suggests that the square transformer is wrongly marked as 4:1.

Another thing that strikes me as a bit odd is that whereas most 'Hiker's' circuits state '2K high impedance 'phones', this one recommends a low impedance 5" PM speaker with no output transformer, which is a bit perplexing.

Pic 1: Redrawn 1951 Hiker's 2 Circuit.
Pic 2: Upright square transformer.
Pic 3: Round transformer.
Pic 4: Original 1951 Lamphouse Annual article.
Pic 5: Original 1951 circuit before tidying it up.

[VT FUSE]

I think I may have the answer to the recommendation of a low impedance speaker being specified and the probable historic root for the obvious error.

Back in the 1930's and early 40's, publications such as popular mechanics and books like "Radio for the Millions" would publish a design that used valves like 1q5, 1c5, 1s4 & 3s4 in the output stage and specify a high impedance "Dynamic permanent magnet speaker" this term was frequently shortened to "Dynamic" but I have seen texts calling for "permanent magnet speaker" and no expected output transformer, typically 8-10k pri to 3 Ohm secondary.

The above fell out of favour post WW2 and we quickly forgot about dynamic and ancient reed speakers.

Some excellent information on LF intervalve transformers from David G4EBT, his redrawn diagram is a big improvement on the oft smudged ones scanned from 85 year old publications on cheap paper.

Thank you David!

Mike

[David G4EBT]

Thanks for reading the thread mike and for your comments.

Interestingly, in the same 1951-52 Lamphouse Annual that the 'Hikers Two' article appeared (pages 112 - 115) recommending a 5" Rola speaker, on page 62 there is a Rola PM speaker advert, mostly 3.7 Ohm impedance, mentioning that 'electrodynamic speakers are rapidly becoming obsolete, but if anyone needed one, they'd do their best to try to find one'.

So, it does seem that they were saying use a low impedance PM speaker without an output transformer.

In any event, if nostalgia triumphs over common sense and I do launch forth and build the 'Hikers Two', I'll use Hi Z phones.

https://www.worldradiohistory.com/NEW-ZEALAND/NA-Collection/Lamphouse-1951-52.pdf

On page 115, there is an article with comments from 'Rola' speakers headed 'Permanent Magnet Speakers are here to stay'.

It should be readable, (at least from the above URL), but I've attached a summary.

I guess that the war years, with the focus of manufacturing & R&D being on the war effort, it meant that little was done on developing domestic appliances, though many of the advances - more powerful magnets, electric motors, transformers and other electronic advances - benefitted peacetime appliance innovation in the post-war years. And of course, for hobbyists, all the ex WD equipment and components, the enjoyment of which for many, continues to this day.