17-02-2016, 10:53 PM
That's very impressive. I've built several crystal sets over the years with variable results. When I lived in Birmingham in the 60s, we lived about 8 miles from Droitwich and I had about 100ft aerial up the garden and could receive Radio 1,2 and 4 from Droitwich and Radio 3 from Daventry using a single Repanco DRR2. I'm sure at one point I received a very weak Radio Luxembourg. The selectivity wasn't that good though. I built a set with two DRR2s coupled by the reaction windings which was more selective but did require careful alignment of the trimmers on the variable caps. However selectivity was achieved at the expense of sensitivity.
Now we've moved to Bradford we are line of sight to Moorside edge so I tried the single DRR2 but the selectivity wasn't brilliant, the tuning control just served seemed to serve as a balance control between Talk Sport and Absolute Radio. I tried another twin DRR2 circuit which was much more selective, being able to tune in 5 Live, Talk Sport and Absolute Radio separately. I've recently tried another single tuned circuit with a larger diameter coil. This proved to be more selective than the DRR2 as on the bench without an aerial I could see the three stations from Moorside Edge on a scope connected across the coil. With a detector and diode all three could be tuned in. I've been using a pair of Sennheiser HD414 headphones but I'll have to try connecting it to an amplifier. When I get time I'll have to try a loop perhaps even try a LW loop and see if I can receive Radio 4 or RTE1.
Keith
Now we've moved to Bradford we are line of sight to Moorside edge so I tried the single DRR2 but the selectivity wasn't brilliant, the tuning control just served seemed to serve as a balance control between Talk Sport and Absolute Radio. I tried another twin DRR2 circuit which was much more selective, being able to tune in 5 Live, Talk Sport and Absolute Radio separately. I've recently tried another single tuned circuit with a larger diameter coil. This proved to be more selective than the DRR2 as on the bench without an aerial I could see the three stations from Moorside Edge on a scope connected across the coil. With a detector and diode all three could be tuned in. I've been using a pair of Sennheiser HD414 headphones but I'll have to try connecting it to an amplifier. When I get time I'll have to try a loop perhaps even try a LW loop and see if I can receive Radio 4 or RTE1.
Keith