Denco Coils

Hi Ivan,
That was interesting. I never thought about looking there. As you say they are rather expensive.

I also notice that the lower coils with the solder terminals are very early Denco, ca 1945, before the plug-in coils. They look like MW amd LW coils.

I don't think I shall buy any of them, not at that price.

I will shortly buy myself a 3D printer and I am presently working on modelling the coils. I have a heap of B7G valve bases and the thought was to use some of those to make my own retro coils. I am collecting pictures and data for them and the link you provided was a very good source. Thank you very much.

Very best regards Harry, and welcome back to the forum

Hi,
I tried my chance on eBay. Denco coils can still be found, although not for cheap:

http://www.ebay.co.uk/sch/i.html?_sacat=7275&_nkw=denco%20coil


BR from Ivan

Hi Glenn,
Thank you for the info. A couple of the pages look familiar but there are loads there to investigate. Thank you very much for sharing the info.

Yes, I do indeed want to build an HF receiver using Denco coils. That I have always wanted to do, but I never had the money to buy them until about 1970. But by then it was too late. I did manage to get a single coil for range 4 for a single valve regenerative receiver and that worked beautifully. I used several different tubes and the final version use an EF90 (the ones that were distinctive by the blue dye inside the envelope).

Before this I had a Philips EE10 kit and used the A3 receiver a lot of the time. I was able to add regeneration and a second tuning capacitor to get decent CW / SSB demodulation at 1.8mc/s and 3.75mc/s. This was in the mid 60's.

Now that I have 33% retired I thought I would gather as much info as I can. I have a 3D printer so I can create some of the "vintage plastic" parts.

there used to be a project in Practical Wireless (UK) in the late 60s for a 1.6mc/s IF communications receiver, on the same lines as the heathkit Mohican receiver. Wouldn't it be great to build something like that?

Perhaps they are old dreams! But so was my Nascom computer :-)

Very best regards from Harry - SM0VPO

Hello,

You could look at:

Alternatives to Denco coils:
http://www.hanssummers.com/images/stories/transistor/dencoalt.pdf
via: http://www.hanssummers.com/transistor.html
Make your own Denco Coils:
http://www.vintageradio.me.uk/radconnav/altdenco.htm
http://www.g4dmp.co.uk/dencocoil.pdf
http://www.vintageradio.me.uk/info/coilnav.htm
http://www.vintageradio.me.uk/info/dencocoils.htm

What is the purpose to ask for them?

Make your own receiver?
...


Supplemented by:
https://web.archive.org/web/20181107174414/http://ns2.miscdotgeek.com/images/stories/transistor/dencoalt.pdf
https://web.archive.org/web/20181107174530/http://qrp-labs.com/images/hanssummers/DencoMaxiQcatalogue.pdf
https://web.archive.org/web/20180831083212/http://www.g4dmp.co.uk/dencocoil.pdf

http://www.vintage-radio.net/forum/showthread.php?t=49227

Jim Jobe posted an MS-WORD document on another forum with some coil-winding details. See the above link.

I note that he listed ranges 3 to 5 but did not include ranges 1 and 2 (LW and MW).

I do know that the MW main winding would be about 85 turns (65 on a ferrite rod)
and the LW I believe in the region of 350 turns.

I hope that this info is useful, and that it answers you question Densil.
BR Harry

Hi once more,
Does anyone have any memories of the old Denco coils? I remember buying a green coil and making a regenerative receiver for 160m and 80m bands. I always wanted to get the full range of coils for transistors but they were off the market by the time I got around to doing anything. I saw that they were were later manufactured by Q-Max, but sadly I waited too long for that.

As a kid I did cadge (tygga) an old LW/MW/SW radio from a friend, and i coupled the antenna circuits into the Philips EE8 receiver. I was then able to select different bands and listen to loads of other stations. But I laways regret not following my desire to get the tube and transistor coil sets. I know you can still get the aluminium cans that were used as packaging and RF shield after installation.

Anyway ...

I have recently used a 3D printer and found that you can use them to create anything. the though occurred to me that the old Denco range of coils were rather special.

Does anyone have any information? such as the coil outside diameter? Turns? etc. I found one site listing the bands (approx):

1 - 150khz - 400kHz
2 - 515khz - 1545khz
3 - 1.67mhz - 5.3mhz
4 - 5mhz - 15mhz
5 - 10mhz - 31.5mhz

Still searching.

Best regards from Harry
SM0VPO and EA/SM0VPO