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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 14th Oct 2017, 2:45 am   #1
Goodizzy
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Join Date: Jan 2016
Location: Lynchburg, Central Virginia, USA.
Posts: 137
Default A few Ferrograph 3A

Good evening,

I have had sitting on my shelf about a year a Ferrograph 3A/NH. (The 15ips version with 110v motor). The unit came with a 2A manual and schematic seems quite similar. I thought I had read awhile ago that there was overlap with the model numbers and this one was sold overseas.

I picked this recorder up cheap at an estate sale and am looking to restore now that I have the time. I only know it was in use at some point by a collector who was the original owner and that it had been kept out of heat and cold.

Everything looks good visually on the unit. No burned out componenets, motors will hand spin, etc. A few questions-

1. I am going to completely recap the power suppy electrolytics. There is a 16+16uf can following the EZ80 and (3) 16+8uf further down the HV line. I don't want to go to the hassle of restuffing cans, and I think I can either hotglue/ziptie or even put a turret board in there if I need to to accomodate axial caps. Would it be ok to increase the values of the caps?

2. The manual says that the 110V 60 cycle model has a special pulley fitted to the capstan motor. I don't see a pulley or the remnants of one. All i see are two rubber idler wheels that probably need to be reformed. I can see where the rubber has worn on the capstan sleeve as well.

3. Somehow in taking apart or in transport I managed to crack the top wafer (phenolic?) of the L5 oscillator coil. The entire coil is sealed and it certainly looks cosmetic, but will it effect performance? (Edit: picture is upside down- sorry)

I appreciate anyone taking the time to read this thread and respond. This place has been a wealth of knowledge for me over here. Cheers
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Old 14th Oct 2017, 3:15 pm   #2
SteveCG
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Join Date: Jun 2009
Location: Herefordshire, UK.
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Default Re: A few Ferrograph 3A

Goodizzy,

Re 1. - Do they actually need changing? If not then I'd concentrate your efforts on the other capacitors first, as if they are of the wrong make they will be leaking electrically. The 2A used ordinary paper capacitors, whilst the 4A apparently used Mullard mustard coloured capacitors. These Mullard ones seem to have survived the passage of time and so don't need changing - although I would suggest checking the voltages around them to confirm this point. If you decide that the electrolytics need changing then there is no reason to increase their values, as the tape-recorder works fine with Ferrograph's values. Indeed the most critical one NOT to raise in value is the one connected directly to the rectifier's cathode.

Re 2 I think the ratio of the capstan motor shaft diameter, where it is in contact with either of the idler wheels to the actual capstan is the critical dimension here. Be aware that there were 110V 50 c/s machines sold by Ferrograph - but clearly not in the USA or Canada.
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Old 14th Oct 2017, 10:16 pm   #3
flywheel
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Location: Leicester, Leicestershire, UK.
Posts: 68
Default Re: A few Ferrograph 3A

Nice to get the high speed version, as they although only mono the heads are best at higher speeds (gap probably too large for 3.75ips) and they can still deliver a really good sound.

1. I agree they might not need replacing (even though well beyond the life expectancy for electrolytics). Surprisingly the two can type caps in the amp more often fail, often with complete loss of capacitance, but the job they do can be taken over by small new axial lead types. There's a recent thread on the Series 4 on here where one comment attributes this to them being - ironically - less stressed, and these caps do indeed run at well below their rated voltage.

One capacitor I really would replace is C15 on the tag board behind the 15ohm socket. This is prone to go electrically leaky, which will drive the output tube grid positive and could take out both the EL84/6BQ5 and output transformer primary through excess current. C15 is one of a number of the paper in oil types you'll see in clear insulating sleeves. The sleeves are often sticky through deterioration of the plastic (acetate?) but the caps themselves don't usually leak oil. If they do, handle with rubber gloves and dispose of as hazardous waste - that stuff may be now-banned PCB. There's a good case for replacing all these caps because they tend to go electrically leaky. (See the pictures in the Series 4 thread which show by the time it was made (probably 1962 for this one) they were using the mustard cement cased polyesters which are good to this day.)

2. You should see a stepped brass pulley on the capstan motor spindle. If all you see is the steel spindle that's not good news - you will need to get hold of one (60Hz version - slightly smaller diameter than 50Hz) somehow. If the neoprene ring on the tape capstan is too worn - or worse, uneven and hardened - this will need replacing (that's the whole flywheel assembly, unless you can somehow replace the neoprene ring - I've often wondered how that could be done, and should be possible with modern materials).

3. The varnishing of the oscillator coil assembly should hold it together okay.

Ferrograph collectors over here should have most of the parts we're talking about if you really get stuck.
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Old 15th Oct 2017, 3:24 am   #4
Goodizzy
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Default Re: A few Ferrograph 3A

Much obliged for all the replies. I will post a few pictures as I get on with the restore.

I should have clarified that I will be replacing all the HV electrolytics as well as the coupling caps. I agree that leaky caps are not worth a blown OT for such a cheap part.

Good news on the inductor, I was hoping it would be alright.

I must have misread the manual or something was lost in translation as I read pulley to mean the rubbery, stretchy thing that goes between two wheels. Here you are meaning what I would refer to as a sleeve. This Ferrograph does indeed have the brass sleeve fitted stop the steel spindle so I'm in good shape!

I'm excited to keep chugging along with this, but the insides of this thing were an absolute mess. Filter cap grounds grounded to the chassis, random other chassis ground, and no lead dress whatsoever. It is taking some time and masking tape to get through it, but I'm determined to get his thing back in top shape.
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