Recent content by davemartin

It's not that I don't want to help you any more, it's just that with out at least a frequency counter to connect to the test points you wont have a clue as to where the radio is going. The reason the other channels are not working could be simply that the VCO or mixer stages don't have the...

These codes mean nothing to your Royce the loop mixing frequency and the N codes are totally different from the 148 using the MB8719. Let me just say that what ever channels you do get out of the Royce WILL NOT match with those from the 148,142 etc. You may find that that 1 radio has say...

I suppose I made the fatal mistake of thinking that you had a least a frequency counter! I sounds like you have very little or no test equipment so the best thing is to put it back to normal until you have some. Do you even have a multi meter? At least then you can do some basic checks. Dave

Which channel did you try it on? It is probable that the radio has gone out of lock. now that I would need the circuit diagram to determine what was the VCO coil. The radio should work normally in one switch position if you have done it right. Dave

Forget the Expander 240 try this instead Try this circuit, it costs peanuts to make and is as good as the Expander 240. Dave

Confusion solved! I now know where the original confusion over pins 5 and 6 came from! The Royce had a earlier version that used 2 programmable dividers as part of the PLL, MC14526 and MC14568 the latter one didn't use pins 5 or 6 (N codes /64 and /32 so pulling them both high would have...

Yeah if pin 14 is connected to any tracks already (which it may not be as it isn't used normally) cut the track so it is no longer connected. If a track passes either side of the pin, cut both sides leaving pin 14 isolated and then use a little jump wire to connect the 2 bits of track back...

You simply make sure pin 14 is isolated from everything else, then connect a 10k resistor one end to pin 4 and the other end to pin 9 (gnd). Now take a single pole single throw switch and connect the centre pin to pin 14 then say the lower pin to pin 9 and the upper pin to pin 18, done! fodendaf...

Looks the same as a old UKFM Shogun, obviously not the same in side as ones AM and the others FM and the board in the Shogun was purpose made FM only. If I recall made in Japan. Dave

Pin 14 is the one you want, it switches the internal code converter giving two sets of N codes, with pin 14 low you get N codes 203 to 329 and high gives N codes of 147 to 210. So assuming that the high setting is normal then putting the pin low instead will move all your channels up by 560Khz...