My Grandad passed away recently. When clearing out his house I found this old Pilot radio. I'd love to get it working. I have a basic knowledge of electronics but I'm out of my depth here. It turns on and you can hear static, but that's it.
Hi Paul, welcome to the forum. 👍 You've landed in the right place, there's plenty of members here with radio expertise.
First things first, could I please ask you to provide the model number of the Radio? Pilot made many sets and to assist us to assist you, we need to know the exact model. The number should be printed on the fibre card back. If you're not sure take a good clear, focused picture of the front and rear, so we can help figure out which it is. Once we know this info, I can make the service data available to our group to enable them to guide you through the repair.
p.s.
I suggest for now you don't turn it on again, this is just in case there is a fault with the audio coupling capacitor. You might also get a fright should the mains filter cap across the line lets go with a very loud bang.
If the audio coupling capacitor is electrically leaky, it could be putting +ve volts on the output valve's grid, which is not good long term for the health of the valve. Also, we want to protect the output transformer, as both of these are sometimes expensive and occasionally difficult to source. This is all the worst case scenario, so don't fret.
Well at least it has a proper mains transformer so uses in isolated chassis. It should be relatively straightforward to sort out provided certain components are attended to. Chances are it will need a handful of capacitors. Unlikely any valves will be faulty but even if you do need any, they are readily available. The fact that you heard static is at least a good sign since it means that the output stage is working and something is at least happening in the receiver stages but as Chris says, don't switch it on again yet to avoid possible damage to critical components.
What is your level of expertise? Do you have a test meter (needn't be anything special)? Are you OK soldering and reading circuit diagrams?
I suppose first thing would be to obtain the circuit, then carefully vacuum out the worst of the dust and then remove the chassis from the cabinet.
A bit of research reveals this radio was made in Ireland on licence by the Brownlee Bros and has a way different valve line-up than one might expect. 12AH8 6BA6 6AT6 6BW6 6U5G 6X4. This made tracking the circuit difficult. The "Clipper" T118 was not a match. However, the Pilot Mariner MKII uses the exact same valves. Interesting that too was made on licence by the Brownlee Bros of Ireland. Interestingly reading the RM article it states the Mariner MKII was based on the UK Pilot Blue Peter, but location components differed somewhat.
It's all rather incestuous, but I'll see what I have in my library, you may end having to use bits of all the cct's.
OK, the following might help, the plan view of the top-deck looks to sort of match your set, there are some minor differences as detailed above. The next is the underside plan view, does that match in any way? If so or very close, then the cct below is likely to be of help. As I said above you're going to have to be creative with this to piece together all the info.
It looks a nice radio. As mentioned, it should be straight forward to get working with just a few replacement capacitors. Of course, that is easy for me to say, but as you are not familiar with equipment such as this, it may seem a bit daunting to begin with.
One thing to be VERY careful with, aside from the afore mentioned precautions, is that the ferrite rod aerial that is hanging out from the set is extremely fragile. There are some very fine wires attached and it must not be allowed to knock into anything. If and when you remove the chassis from the cabinet, I would be inclined to wrap the rod in bubble-wrap to protect it.
To understand the black art of electronics is to understand witchcraft. Andrew.
OK, the following might help, the plan view of the top-deck looks to sort of match your set, there are some minor differences as detailed above. The next is the underside plan view, does that match in any way? If so or very close, then the cct below is likely to be of help. As I said above you're going to have to be creative with this to piece together all the info.
Hi-
Sorry it has taken so long to reply. I removed the chassis to check the underside. I find it hard to tell, but if I think that it is perhaps different to your photo?
Ok, thanks, I'll do that. Hopefully it hasn't already gotten damaged.
I have a basic understanding of resistors and capacitors and have a limited amount of experience with soldering, enough to get by probably. You're right though, I wouldn't have a clue where to begin, as far as knowing what to replace.
It would be worth checking the resistance of the sound output transformer primary winding, these can go open circuit if over run or left somewhere damp.
Also check the windings of the mains transformer for a similar problem although not as likely to be faulty.
You do this without power being applied so it’s a safe and simply test.
Judging by the above photo's, I would say it looks to be in very good condition with no sign of corrosion from damp. The mains transformer has likely proved itself to be ok as you have already powered the set, but well worth checking the audio output transformer. Expect a low resistance on the secondary (speaker side), and perhaps a few hundred ohms on the primary (valve side).
As the set is a fairly simple design, it should be possible to trace through the mains input to the on-off switch. Here, the mains may go directly into the mains transformer, but it is likely that there is a capacitor enroute across the mains. This capacitor MUST be removed or replaced. It most likely will be cylindrical in shape and of a wax construction marked TCC. If left in place, it could explode when you come to power the set. However, you could be lucky and there is no such capacitor fitted.
I can see other TCC capacitors, a group of three at the lower right of your last photo above. These may be left for the time being and replaced later, but another similar capacitor (or two?) that are lurking close to the the third valve base in from the left (around the 6AT6 and 6BW6) is most likely the audio coupling capacitor from the 6AT6 to the sound output valve 6BW6. Another one could be a tone corrector across the output transformer primary. Certainly the audio coupling capacitor really must be replaced to avoid possible damage when you come to operate the set again.
Any flat looking capacitors should be perfectly fine and these are a mica type enclosed in wax. The other cylindrical capacitors as mentioned are a waxed paper type and will be troublesome due to the poor insulation offered by their waxed paper construction. Nasty things !
It is a good sign that you could hear static sounds from the speaker when it was powered as this proves that the the bulk of the set is essentially working. Once you attend to the above, you may well be able to tune the set into a station.... Radio 4 on LW is a good bet, around "BBC Light" on the dial.
PS.... Make sure you have LEADED solder. Unleaded will give poor joints when mixed with existing connections in the set.
To understand the black art of electronics is to understand witchcraft. Andrew.
Suitable capacitors for replacement will be metalised polyester film types, such as this below. They can be found on places such as ebay for fairly modest cost. The approximate closest value to the original is ideal, but it is VITAL to use ones rated at voltages of at least 400v, and at the very least 1000v if used on the mains.
To understand the black art of electronics is to understand witchcraft. Andrew.
From left to right, the first device looks like a thermistor. Normally used to prevent a current surge through series wired valve heaters and scale lamps upon switch on. However, they are not normally used on 6.3v heaters as used in this set. Quite exactly the purpose here it serves, I do not know. Perhaps someone else who know's may chip in, but leave it well alone is my advice lol.
The other device is an old style resistor and I would expect it and the gold coloured 25MFD 25V capacitor to be perfectly fine and can be left alone for the time being.
A flat capacitor (500pf mentioned above) will be a mica type and will also most likely be completely fine.
The capacitors in the link you provided will be perfect.
You should only need to replace the wax cylindrical ones, (typically in the range from 0.01 to 0.1uf).
To understand the black art of electronics is to understand witchcraft. Andrew.
