Gulp.... Ferrograph Series 4

[Ferrograph723]

My latest acquisition.

Last powered on in 1975 and currently home to a considerable number of spiders.

I have no idea where to even begin. Any hints and tips gratefully appreciated.

[Radio Wrangler]

Step number one is a general clean-up and the outside cosmetics.
Step two is getting circuit diagrams and service information.
Step three is a general visual inspection looking for split capacitors and other visible signs of damage like heat-discolouration.
Step four is replacing the DC blocking capacitor between the driver valve anode and the first grid of the audio output valve. Any leakage here does a lot of damage.
Do these BEFORE applying any power.

Then you're into cleaning lubricating the mechanicals, looking for hardened rubber in the drive wheels and the pinch wheel, measuring resistors - higher value ones are particularly keen to go even higher in value.

When they're working properly, they are a very nice machine and are very robust.

Have a search around on the group, there has been a lot of material on these already.

David

[SteveCG]

Yep, time to move the spiders out !!

A good internal dust and clean is what I would do first.

Next point does it have a mains voltage selector on the back? If so then make sure it set correctly (you never know what the recorder's previous life may have been).

Then I would turn the recorder on but power it up via a variac to slowly sweep up in mains voltage. Failing that you will find 'lamp limiter' circuit on the forum to try instead. The purpose of this is to gently reform the electrolytic capacitors. Do this for only a couple of minutes initially, then repeat again after a few minutes gap. Ideally you would apply a DC voltage to the main electrolytics from a separate power supply unit with a high value resistor in series - say 47KOhms - but you may not have the necessary equipment.

Then without a tape spool on the recorder turn the switch to play and check that the spool holders turn and also the capstan (next to the replay head on the RHS as seen from the front).

That's enough to be getting on with for the moment.

[Ferrograph723]

Thanks Steve & David.

The spiders have now been evicted and the inside/outside given a first clean. I've checked the mains selector is correct (good tip - thanks).

I've downloaded the Circuit Diagrams and Service Manuals. I understand C15 is the critical Capacitor to replace before powering up (David - is that the one you're referring to in your post?).

Steve, good tip on gently loading up the mains - I'll investigate that. I need to replace the power plug as it didn't come with a lead.

The mechanics seem to be in ok shape based on an initial cursory check - no grinding bearings, and everything seems to engage correctly. The rubber wheels look ok and seem to engage with the flywheel correctly, but I won't know for sure until I have a closer look.

Fun times

[Reelman]

You got a bargain there compared for what many others go for. Even if poor outside there are plenty of useful parts inside. Better still that you want to restore it. At least the idlers should be ok. Worth asking on here if anyone has a spare 3 pin Bulgin mains connector.
Good luck with it, it will be well worth it.
Funny though, 10 years ago I struggled to sell the valve Ferrographs for a fiver!
Peter

[SteveCG]

I've dealt with a Ferrograph Series 2 and its 'paper' capacitors were electrically leaky - although they looked alright visually. I've been told though that the Series 4 used better capacitors and they may not be leaky - however this information should not be relied upon without checking them.

I've never dealt with a Series 4, but it looks a lot like a Series 2, in which case, as Radio_Wrangler advises, you will need to regrease the mechanics. Remember to keep grease and oil off the rubber idlers.

[Uncle Bulgaria]

Good luck Ferrograph723!

You may wish to look at my thread on restoring a Series 4 I got on Freecycle. It has ended up being quite comprehensive, especially MS660's many edifying posts. I took the machine apart down to its constituent nuts and bolts, recovered it and am currently using it as my bedroom record player amp & speaker. The inside was similar if not worse than yours, so it's eminently possible!

You can find it here.

I replaced the filter/reservoir capacitor the other week, but have still not quite got round to aligning all the tape sections. It plays, but not as well as it should, so the thread is on-going!

I really went wild and recorded all the screw locations and types so I didn't end up with a pot of 'where do they go?' washers and other parts, and so I'd be happy to share the notes I made with you if you need a hand.

[DMcMahon]

Looks nice and not bad condition, good luck with the restoration.

I have 3 pin mini & full size Bulgin mains cables spare, if you need one FOC then let me know.

David

[reelguy]

The deck looks as if its not had much use. The play control hasn't lost any paint which is a good giveaway if its been heavily used. Idlers look good also . Not familiar with the series four but not very different from the later models. Good clean and it will probably be a nice recorder. good luck with it.
Peter Reelguy

[Ted Kendall]

The major difference between the series four and five was the halving of the capstan diameter and doubling of its speed on the latter to improve speed stabilty. The four was by no means bad by contemporary standards, but was being nudged by the Tandberg 6 and the early Revoxes in its domestic price bracket, both of which had significantly better wow figures.

[flywheel]

Originally Posted by SteveCG

I've been told though that the Series 4 used better capacitors and they may not be leaky - however this information should not be relied upon without checking them.

This is a late-production Series 4 (the change to the smaller metal-capped amplifier knobs dating from 1962). Although some of the electrolytics may have lost capacitance and will have to be replaced (filter ones in the amp can be supplemented by modern axial types in parallel - the originals are not likely to be electrically leaky, but if they are should be disconnected). The others should be fine - including the critical one mentioned above - as you'll find they're the sought-after Mullard 'mustard' polyester types.

[Ferrograph723]

IT WORKS!!!

After a few hours cleaning and checking everything to the best of my untrained abilities, I knocked up a Lamp Limiter (had to use a 120w halogen floodlight as normal 100w incandescent bulbs are no longer widely available). I then made a temporary power feed (huge thanks to David for the kind offer of a Bulgin plug) and connected it all up.

I followed the advice above and powered it up for just a minute or two at a time - at standby the lamp was barely glowing so no short circuits, no smoke, no nasty smells. I then tried running the machine - the take-up reel needed a nudge to get it moving but after a couple of minutes was spinning at full speed... the capstan was rotating nice and tight against the idler and all looked good. Another cool down and it was time to load a tape up. The playback speed is a little slow - I was thinking it might be due to the lamp limiter limiting the current at the bulb was burning pretty bright by then - but the manual reckons the Ferro's power consumption is 110 watts, so a 120 watt bulb should have given it enough juice to run so might be something else I need to look at.

The amp works fine - amazingly even when changing the volume (/gain) there's no crackle from the pot.

I've powered it off to rest now until I get a proper Bulgin. Then I'll try a full test. Then it's on to stripping, lubricating, cleaning and polishing!

Thanks to all the help on here from other posters - much appreciated.

[DMcMahon]

See PM about bad news about the Bulgin plug.

[flywheel]

Not sure if oiling motor or other bearings has been mentioned, but best do that asap before use as they'll likely be on the dry side.

Oiling the motor bearings is really tricky though - needs a fine long-reach pipette or similar. The capstan motor's not too difficult, but the top bearings of the reel motors are a pain to get to (I usually remove the reel carriers to do it).

A fine but not too fine oil of about SAE20 seems best for this, but I use SAE30 for pinch rollers and idlers because of the low rotation speed and sideways thrust on the bearings. (There may of course be other views on lubrication!)

[Ferrograph723]

Originally Posted by DMcMahon

See PM about bad news about the Bulgin plug.

I got the PM you sent yesterday David - have you sent me a second one? (if so, I can't see it in my inbox?).

[DMcMahon]

There were 2 PMs, I will resend.

[Hartley118]

Originally Posted by Ferrograph723

IT WORKS!!!

After a few hours cleaning and checking everything to the best of my untrained abilities, I knocked up a Lamp Limiter (had to use a 120w halogen floodlight as normal 100w incandescent bulbs are no longer widely available). I then made a temporary power feed (huge thanks to David for the kind offer of a Bulgin plug) and connected it all up.

I followed the advice above and powered it up for just a minute or two at a time - at standby the lamp was barely glowing so no short circuits, no smoke, no nasty smells. I then tried running the machine - the take-up reel needed a nudge to get it moving but after a couple of minutes was spinning at full speed... the capstan was rotating nice and tight against the idler and all looked good. Another cool down and it was time to load a tape up. The playback speed is a little slow - I was thinking it might be due to the lamp limiter limiting the current at the bulb was burning pretty bright by then - but the manual reckons the Ferro's power consumption is 110 watts, so a 120 watt bulb should have given it enough juice to run so might be something else I need to look at.

The amp works fine - amazingly even when changing the volume (/gain) there's no crackle from the pot.

I've powered it off to rest now until I get a proper Bulgin. Then I'll try a full test. Then it's on to stripping, lubricating, cleaning and polishing!

Thanks to all the help on here from other posters - much appreciated.

Time to give it full mains volts I reckon.

Just check the voltage with respect to chassis on the grid of the output valve with your DMM. If it’s more than a fraction of a volt positive, it’s time to replace the coupling capacitor.

Martin

[DMcMahon]

Originally Posted by DMcMahon

There were 2 PMs, I will resend.

Have resent, maybe more than once !

[DMcMahon]

Originally Posted by Ferrograph723

IT WORKS!!!

After a few hours cleaning and checking everything to the best of my untrained abilities, I knocked up a Lamp Limiter (had to use a 120w halogen floodlight as normal 100w incandescent bulbs are no longer widely available). I then made a temporary power feed (huge thanks to David for the kind offer of a Bulgin plug) and connected it all up.

I followed the advice above and powered it up for just a minute or two at a time - at standby the lamp was barely glowing so no short circuits, no smoke, no nasty smells. I then tried running the machine - the take-up reel needed a nudge to get it moving but after a couple of minutes was spinning at full speed... the capstan was rotating nice and tight against the idler and all looked good. Another cool down and it was time to load a tape up. The playback speed is a little slow - I was thinking it might be due to the lamp limiter limiting the current at the bulb was burning pretty bright by then - but the manual reckons the Ferro's power consumption is 110 watts, so a 120 watt bulb should have given it enough juice to run so might be something else I need to look at.

The amp works fine - amazingly even when changing the volume (/gain) there's no crackle from the pot.

I've powered it off to rest now until I get a proper Bulgin. Then I'll try a full test. Then it's on to stripping, lubricating, cleaning and polishing!

Thanks to all the help on here from other posters - much appreciated.

Sounds very hopeful indeed, a good buy !

[Ferrograph723]

Originally Posted by DMcMahon

Have resent, maybe more than once !

Super strange - still nothing has arrived (not even an email notification telling me I have a new PM!). The only PM I have from you is the first one on Saturday. (see attachment)

Don't worry - I'm guessing the bad news is you're not able to send me a Bulgin plug - thanks for trying anyway, appreciated.