Hi Folks,
Pictures to follow, but my latest acquisition arrived yesterday (no time yet even to open the box...) This is from the mid 90's UK shortwave manufacturing boom - The Lowe Electronics HF-150 mentioned in the October Finds thread. It should be fun AND is portable. The antenna inputs include a switchable built in active pre-amp for a short "Whip" antenna, so no need for the less portable long wire. A capable communications receiver, contained in a tough, compact 7.7" x 6.5" x 3.5" package.
Now, this has spawned a small project of its own. The receiver could be ordered with a keypad accessory, to allow direct frequency entry. Alas, this was not available with the set I bought. I do, however have the schematic, and have been able to find the chip necessary to interface a 12 button keypad to the radio. I know it isn't tubes/valves, but this IS a classic radio
I'll update here with progress.
Cheers
Ed
Oh dear, where have I been? Well, at last I took a picture:
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attachment=17743]
I'm very impressed. 30 kHz to 30 MHz. USB, LSB, Wide and narrow AM, Synchronous AM with double or selectable side-band, memories. Smooth tuning in 8 Hz steps, all in a package the size of a couple of paperback books.
Still waiting for the ICs to build the keypad unit.
Cheers
Ed
Hi Terry,
Yes indeed. I remember reviews and adverts in the UK radio magazines when it was available new. Price was about GBP400, compared to the bigger brother HF-225 which was about GBP500. As to prices in the US at the time, I don't know. What made sense to a lot of UK folk was that these radios were quite a bit cheaper than the imported Yaesu/Icom/Kenwood fare of the time, yet offered performance on a par or better.
The only thing they lacked was the fancy front panels - One quickly gets past cosmetics after spending some time listening.
I feel lucky to be able to collect this one.
Ed
Time for the project mentioned in post #1.
This is to reproduce the plug-in keypad controller that was available as an accessory with this radio, and others in the Lowe line. I was able to find a very similar key switchpad and case to the original, and also was able to track down the all important IC required. I have an original keypad that belongs to my other Lowe radio, so was able to measure dimensions and get the correct appearance. Service data includes the schematic for the keypad, and it would also be possible to reverse engineer from the example I have. It was also possible to use that pad to make sure the radio's control input still works before getting started.
I'll document here, with pictures. 1x keypad, 1 IC two transistors and a diode, plus a few resistors and caps. Not too hard I hope
A rather busy weekend limited bench time, but I did get started.
Mounting the keypad to the box required a slot to be cut to pass the pins through from outside. Found I needed to order 2-56 screws to attach the keypad, and the position of the fixing holes is tight with respect to the holes for the screws that hold the box together. It should just work though..
After that, it was back to the drawing board, to start translation of the schematic to a layout on strip board. Takes me back to the projects I used to make as a teenager
. This is about 50% done, and I can work on the remainder over the next few evenings and be ready for building in time for the weekend.
Ed
I'd forgotten what a frustrating business strip-board layout is. However, I stuck to it, and now have all the components on the board, jumpers and cuts placed accordingly. The screws necessary to attach the keypad to the enclosure arrived during the week, and that work was also completed.
Next, I need to wire up the keypad to the circuit board, and make up the connecting cable with its 3.5 mm plug for the radio, and we'll be ready to test.
Cheers
Ed
Done! Pics later. My keypad works after a bit of troubleshooting. One issue was a reversed diode (no power to the chip). I'm sure I checked that little fellow more than once, and must have flipped him around while trying to bend the leads to the right pitch. Then I had a bit of trouble with connections between the key switch matrix and the main board - showing up as a lost row or column on the "telephone" dial.
Honestly, this is the last time I ever use Vero-board (perforated copper strip board). The stuff I have seemed to hate solder, but would happily allow bridges to form between tracks. Very frustrating, and little issues with this added a lot of time today.
However, of course I didn't give up - especially as this is a project for a good little British radio, born just over in the next county from where I grew up. It is great to be able to tap in a frequency (or recall a memory) with this neat accessory, and my repro seems to work happily on either of my Lowe sets
Cheers
Ed
Pics as promised:
A fairly simple component layout:
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attachment=18712]
And here is the unit and the receiver - I'm all setup to receive an important encrypted message on Channel D
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attachment=18711]
I have read your article only now: is it possible to have the wiring diagram and the list of components for the realization of the Lowe KeyPad?
Quote "What made sense to a lot of UK folk was that these radios were quite a bit cheaper than the imported Yaesu/Icom/Kenwood fare of the time, yet offered performance on a par or better."
I can certainly understand that, there was some sort of cult following with Yaesu and Kenwood stuff back then that never made much sense to me. I still see both brands of rigs for sale on C.L from time to time, but many don't seem to get it that the sun has largely set on HAM radio as a growth hobby. Never heard of Icom until recently, and quite frankly the name does not grab me, makes it sound like BPC China junk. In term of British stuff I'm, always open to acquiring an Eddystone, I have a rebadged one downstairs that was dropped at some point, so one of the chrome rails was removed from the front panel.
Regards
Arran