Hi. I have a HRO 7 which works just fine with matching A coil which I have. I acquired some HRO 50 coils, but do not want to work. Is this normal? Will any one familiar with this area, help me out? Thanks. Andy.

Hi,
assuming that the windings that correspond their respective sections are wired to the same pins on the coil forms of the HRO 7 and the HRO 50, they should work as long as they do not go beyond the limits of the basic reciever's design. In other words, an HF radio setup for 160m, 80m, and 40m, may still perform in the 19/20m range, but may not always operate at 15m or 10m.

I think in your case, it is more likely that the pins do not corespond to the same coil, or two leads may need to be reversed for them to work in your set. I would use a DVM to determine the oscillator coil, and the RF coil windings, and see if they match up. If they do, try reversing one pair of the oscilator coil leads.

I am not well versed in the nuances of the HRO rigs, but basic radio theory should apply.

If you did not spend that much on the coils, considering the costs of blank coil forms, it may well be of benefit to either make the changes in the coils you have, or make an adapter to be able to use them, or wind new ones using the old forms.

:Hi. I have a HRO 7 which works just fine with matching A coil which I have. I acquired some HRO 50 coils, but do not want to work. Is this normal? Will any one familiar with this area, help me out? Thanks. Andy.