The Lake DTR7

Built by Carl, GW0TQM

Notes on using the DTR7

The DTR7 uses a direct conversion receiver. So how do you tune it in to net with another station? Firstly you have to make sure that the rig is built so that positioning the RIT (clarifier) in the straight up position actually puts the receive oscillator on the same freq as when on key down TX. The fact that the RIT doesn't switch OFF is a shame for this reason- I'd like the variable pot to be mounted on a push pull on/off but there you are. Of course a DC RX will zero beat with an incoming signal when 'netted' so you don't hear it! So, when tuning around the band you have to sort of sneak up on a signal sidways, then rush pash and sort of slide back sneaky like so that the two points where you can just hear a low note are about the same distance from the final vfo position as each other...

Then you can use the RIT to (a) check that similar swings in each direction produce similar notes ( a better check of correctly netting with the received signal) and (b) setting a pleasing cw pitch... and of course you check BOTH sidebands to see which is the quietest.

I use a nifty little CW key on a belt that straps to my knee, great for operating in a field/in the car - it's perfectly placed and so long as you remember it's there, it doesn't hurt a bit...

Many thanks to Carl for the above notes and for submitting the hand drawn picture of his rig. Carl has his own web page, well worth a visit!

The DTR7 is one of a range of QRP rigs and equipment made in UK by Lake Electronics, 7 Middleton Close, Nuthall, Nottingham, NG16 1BX. Kits come with all components, punched cabinets, nuts and bolts, in fact everything needed for the successful completion of the project. (G3YCC)

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