At last I've finished restoring these very similar radios. The each have identical cabinets, a similar dial and speaker fret, both are TRFs, but the layout of the components differ slightly as does the type of coils used and the valve line-ups. The Portadye Princess uses two 12BA6's, a 35L6 and 35LZ, whereas the Noble line-up is 12K7, 12J7, 35L6 & 35LZ. the total heater chain of each set is 94V at 0.1A. In each case the dropper resistor which consisted of 550R & 260R had burnt out - it looked a bit puny for the task in hand, so it wasn't surprising. I'd mentioned in another post that I fitted two 50Watt metal clad resistors, (270R & 270R), but metal clad resistors must be fitted to a heat sink or de-rated, so I made a heatsink for each set from 5mm think aluminium angle. After initial warm-up, the heat sinks stabilised at 50 C - 122 F, so I was happy with that.
Both sets use a 50K anti-log pot for the reaction/volume control with a single pole switch. An anti log track is a mirror image of a log track. In an antilog track almost 90% of the total resistance is reached at 50 degrees of rotation. In each case the switch was open circuit but in both cases I was able to bend back the tabs that held the switch to the pot and separate the switch from the pot section to spray the switch with Servisol to restore the continuity of the switch, then reassemble the pot. In one pot the tags on the track had worked loose but I was able to firm them up with gentle taps from a small planishing hammer. I'd have been happier to have replaced the pots, but they're simply not available retail. It may be that a linear track pot would have worked, but my efforts to try to convert a linear track to anti-log with an external network came to nothing.
You can get pots made with or without switches in any value, any type of track by a great little firm 'OMEG' who supply pots to the likes of Maplin, Rapid etc, and give a friendly personalised service. However, they have a minimum order value of £25.00 + VAT, and ordinarily a minimum order quantity of ten. Having spoken to OMEG, I could get them made in the old style metal cans (known as 'P20) with 1/4" shaft and a 4 Amp dual pole mains switch for £5.99 each, but would have to order five, which - with VAT and postage would come to £41.70 - £8.00 each. Great to know that there are still helpful little outfits around such as OMEG in the face of oriental competition, but it's a bit of a non-runner to follow this up as I'd be left with three on my hands, so I'll content myself in knowing that both sets are working nicely, and perform remarkably well on their 15ft throw out aerials.
In each case the twin smoothing and reservoir caps reformed nicely over a period of several hours on my RB cap reformer. (See pics below).
I had a basic circuit for the Portadye Princess, but no circuit for the Noble, about which little seems to have been known. No idea who the firm was or for how long it was in existence. Luckily, though the Princess had been tampered with and vandalised by an inept former custodian, the Noble hadn't been touched, and replacing the caps and dropper was all that was needed to bring it back to life, so I didn't bother to draw out a circuit. All of the valves in both sets tested like new, which I was chuffed to discover.
A few pics attached.
Hope it's of interest.
Both sets use a 50K anti-log pot for the reaction/volume control with a single pole switch. An anti log track is a mirror image of a log track. In an antilog track almost 90% of the total resistance is reached at 50 degrees of rotation. In each case the switch was open circuit but in both cases I was able to bend back the tabs that held the switch to the pot and separate the switch from the pot section to spray the switch with Servisol to restore the continuity of the switch, then reassemble the pot. In one pot the tags on the track had worked loose but I was able to firm them up with gentle taps from a small planishing hammer. I'd have been happier to have replaced the pots, but they're simply not available retail. It may be that a linear track pot would have worked, but my efforts to try to convert a linear track to anti-log with an external network came to nothing.
You can get pots made with or without switches in any value, any type of track by a great little firm 'OMEG' who supply pots to the likes of Maplin, Rapid etc, and give a friendly personalised service. However, they have a minimum order value of £25.00 + VAT, and ordinarily a minimum order quantity of ten. Having spoken to OMEG, I could get them made in the old style metal cans (known as 'P20) with 1/4" shaft and a 4 Amp dual pole mains switch for £5.99 each, but would have to order five, which - with VAT and postage would come to £41.70 - £8.00 each. Great to know that there are still helpful little outfits around such as OMEG in the face of oriental competition, but it's a bit of a non-runner to follow this up as I'd be left with three on my hands, so I'll content myself in knowing that both sets are working nicely, and perform remarkably well on their 15ft throw out aerials.
In each case the twin smoothing and reservoir caps reformed nicely over a period of several hours on my RB cap reformer. (See pics below).
I had a basic circuit for the Portadye Princess, but no circuit for the Noble, about which little seems to have been known. No idea who the firm was or for how long it was in existence. Luckily, though the Princess had been tampered with and vandalised by an inept former custodian, the Noble hadn't been touched, and replacing the caps and dropper was all that was needed to bring it back to life, so I didn't bother to draw out a circuit. All of the valves in both sets tested like new, which I was chuffed to discover.
A few pics attached.
Hope it's of interest.
Regards, David.
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
BVWS Member.
G-QRP Club Member 1339.
'I'm in my own little world, but I'm happy, and they know me here'
