Quirky Amateur radio equipment


Lake DTR3: 80 metre transceiver with Antenna Tuning Unit

 There are two items here, neatly assembled into a home-made box, with a drop-down hinged lid, and a handle on top for easy transportation. I imagine the previous owner used them in a caravan (or boat?) perhaps hooked up to a long wire aerial (or whip in the case of a boat)?

Powered from 12 volts, the pair consists of a DTR3 80 metre CW Receiver andTransmitter in the upper of the two units, and a TU2 aerial matching device with SWR and power meter in the lower unit.

The equipment was on the market a few years ago either in kit-form or already assembled from a small UK-based company.

UK stuff is entirely different from the more common Japanese black boxes and has a unique "made in a garage" look about it. This applies to most things electronic, whether they are heating controllers, washing machine electronics or escalator controllers (which I have recently begun to repair for some local lift maintenance companies. I don't mean to denigrate the quality of the things, it's just their looks. This also applies to Quad, Leak, Roberts and Hacker stuff. There's something unmistakably "British" about them all!

This QRP rig was built from a kit designed and manufactured by Alan Lake of Lake Electronics.

 Here's the marketing information:

DTR Series

Single Band, CW Transceivers

DTR 3-5 (3.5 / 3.6MHz) DTR7-5 (7.0 / 7.1MHz) DTR10-5 (10.1 / 10.2MHz)

These little rigs can produce any output power from less than 25mW to around 8W. They all have a very effective 7 pole low-pass filter resulting in a harmonic level of better than 50dB below the main output.

The receiver incremental tune (RIT) allows about +/- 4kHz of fine tuning around the transmitter. And the stable VFO is controlled by the new Jackson calibrated ball-drive - well known for its clean appearance and smoothness of operation.

Receiver (DC) sensitivity is better than 1microV minimum discernable signal (MDS) and selectivity, with the included audio filter, is around 250Hz @ 6dB. A 12 dB (switchable) attenuator deals with any high-powered AM breakthrough.

 

Power requirements : 12/14Vdc, 1A (key down) at 5W output.
Connectors : 1/4" jack sockets for key and 'phones (8 ohms), SO239 (antenna) and phono (power).
Case : Heavy gauge aluminium, finished in black enamel, with printed acetate facias.
Kit price - £98.70 Built to order - £168.00

Postage (UK) £4.00

 

TU4 Antenna Tuning Unit

Very similar in style to the DTR series of transceivers, the TU4 is conservatively rated at 80W and covers the HF spectrum.

Based on the well proven "L-Match" circuitry, the TU4 can be configured into any of three different arrangements, making it easy to obtain a match with a wide variety of transmitter/band/antenna combinations.

The LAKE "PLANAR" inductor is a feature of the unit. PCB based, the coil is of flat rectangular form rather than the traditional helix. There are several advantages to this system - the unloaded "Q" is around 60, measured at 5MHz, self capacitance is low, about 5pF, and tappings are easily arranged in exponential increments of inductance.

The tuning capacitor is a high grade air-spaced unit made by Jackson.

The built-in SWR meter is exceptionally sensitive. Based on the 'Bruene' bridge circuit, less than half a watt is sufficient to give full scale deflection of the meter at 3.5MHz. Ideal for QRP operation!

GENERAL SPECIFICATION

Frequency range : 1.5 - 30MHz - Power rating : 80 watts (CW) Includes 4:1 Balun for balanced output
Dimensions : 210 x 190 x 85 mm. - Weight : 0.9 kg.
Terminations : SO239 (to transmitter), SO239 to the antenna plus 4mm terminals for direct connection to an end-fed wire, earth, and, if necessary, balanced feeder.
Case : Heavy gauge aluminium, finished in black enamel with silver-grey facias on front and rear panels.
Kit price : £68.00 Ready Built : £88.00

Postage : (U.K.) £4.00


The SSM Europa-B 2-meter transverter

 Another British piece of amateur radio gear, this time based mainly on valves rather than transistors.. This "transverter" represented a cheap way of getting onto 2 meters as it merely upconverted the 10 metre range of a standard HF transceiver to that VHF band. Admittedly one had to provide a power supply and hide it away under the bench, but, overall it cost a lot less than an equivalent Japanese black box and provided increased output power over the latter, with its Mullard QQV06-40A output valve squeezed onto the chassis.

As they used to say. "Why not make use of the high specification of that really expensive HF transceiver on two meters?"

Although a good idea they didn't really catch on because the new Japanese stuff looked so good, and despite their astronomic prices and disgraceful "price fixing", reminiscent of the goings on in the British radio industry of yesteryear, the latter sold well. The position of the meter seems to suggest the designer forgot it when laying out the chassis.

 

 

 

 
 

 Click the circuit diagram above to read the user manual that came with the transverter.


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