Ferrograph series 7 Grand Opening - UK Vintage Radio Repair and Restoration Discussion Forum

NorfolkDaveUK · 27th Aug 2018, 10:38 am

I`ve started a new thread because the other one was more about ferrograph v revox in the end soo ..lol

To say I`m more that a little shocked to find what I have in side here is an understatement , I assumed because it had sat in the shed for 20+ years in the same spot and has stuff piled on it , got a bit damp I would find corrosion , rust critters etc in here , however ..........(see pics)

So I guess we can draw from that that at least the case is a winner for this machine . . It had a few cobwebs , but don`t we all at our age .lol .

I would call that a result , Now to make it work . ..........

NorfolkDaveUK · 27th Aug 2018, 11:13 am

Can anyone tell me if this has some kind of safety feature that stops you using it outside of the case ? Now its out nothing is working except for the power light . Could be related to the smoke of course ..lol

Thanks

terry123 · 27th Aug 2018, 11:17 am

Have you put all the fuses back in after the cabinet removal? If so you may want to check that they are still intact and have not become detached inside the holder.

Terry

NorfolkDaveUK · 27th Aug 2018, 11:28 am

It came out nicely without removing them bud. I checked them though and they are all ok . The last time I played with it , it started smoking just before I turned it off , so I`ll pull the power unit . I would have thought that came from the dirty great wire wound at the top there though. its covered in dust

On a different note , this has some really weird wheels in it . I bought some of the originals to put in it but the ones in it are pale blue and rock hard . Now I though because they are rock hard they were borked , but the worked ok ? you know of these things ?

terry123 · 27th Aug 2018, 11:41 am

Hi

sounds like they are some sort of past replacement.

Terry

NorfolkDaveUK · 27th Aug 2018, 11:51 am

Yeah thats great because they haven`t melted all over the place they have just gone hard . They are 3 times thicker than the originals too . I think i`m going to have to replace them because being rock hard can`t be good for the other parts can it . (see pic)

Terry do you have a schematic showing the voltages ? The one I have (hfe) doesn`t ..ta.

NorfolkDaveUK · 27th Aug 2018, 12:25 pm

Nevermind Terry i found it , the "tape in switch " needed a good clean . Works treat now , it needs a lot of cleaning but other than that i think its good to go pretty much

NorfolkDaveUK · 27th Aug 2018, 12:29 pm

Does need a pinch roller if you can PM me a price please Terry .

Cheers

NorfolkDaveUK · 27th Aug 2018, 12:56 pm

You know I dont think these were designed to be soft at all . I think these are "goo busting" replacements . I`ve not heard of them at all , but these are definitely plastic and not rubber they are screwed to the brass wheel . The pinch roller is the same ..

dave walsh · 27th Aug 2018, 1:05 pm

Good result Dave. I don't think mine has been in a shed so I will to take a look when I go North this week, after your positive experience

I'm not clear about you just having a power light when you took it out of the case and then cleaning the "tape in" switch. Did you mean the deck was running but you couldn't record/playback

Dave W
Bexhill

NorfolkDaveUK · 27th Aug 2018, 1:11 pm

No it was completely dead apart from the "reset" light . after moving the tensioner arm up and down a few times the light went out with the tensioner up and we were off .

I dont know what to do about those wheels now . I think i`m going to put them back in after I clean up the motor shaft and see how they perform . I can imagine that when it gets hot in there they are going to soften up slightly and might well perform pretty well . we will see.

Once I`ve done that I`m going to re-cap the amps and I`ll let you all know how its going this evening .

Peace !

dave walsh · 27th Aug 2018, 1:18 pm

Oh right Dave. I thought that there must be a "missing link". It's similar to the tension piece on the Akai 4000 isn't it. That only comes into use on one position of the mains switch. Quite a few people used to post about that as it wasn't so obvious if you didn't have the Handbook!

Dave

NorfolkDaveUK · 27th Aug 2018, 2:16 pm

I knew it was there bud but it wasn`t working , it was filthy , so was activating when it felt like it ..lol A quick clean with some alcohol brought it into my way of thinking .lol

NorfolkDaveUK · 27th Aug 2018, 4:04 pm

So after now playing with it a bit , I need some help . The output is right side only and VERY low . I have re-capped the amps on the power board assy , problem remains the same . Switch crackle is pretty loud though so i think the amps are ok so the signal is getting lost somewhere it seems . Can someone that knows the machine tell me where to trace the signal please . The schematic I have is awful . No VU action at all .

The plastic wheels have GOT to go they make a HELL of a racket , its almost unbearable . Good idea for stopping the goo maybe . terrible for keeping the noise to a minimum .

transport is now working , how much fun is the wind thing ..haha ...

The audio that is playing (albeit really quietly ) sounds really clear and crisp . Just need more of it ! and on both sides !

NorfolkDaveUK · 27th Aug 2018, 5:14 pm

OK i got the sequence , replay pre-amp , meter and tone then power amp . .... , there is no meter action at all so I think the issue is right back at the preamp stage so I`ll sort those out first !

TonyDuell · 27th Aug 2018, 5:19 pm

Now I've not started on my Ferrograph 722H yet, so I am working from the manual only. The service manual I have (on paper, it was given to me with the machine) has very clear circuit diagrams, but the scanned version I found has them as 4 overlapping sheets which I guess are not clear. Alas I don't have a larger-than-A4 scanner so I can't produce a better version from my manual.

The unit is quite modular. The signal from the replay head goes to the replay amplifer. The output of that goes to a preset level control and monitor switch to the meter/tone control board. Then to the main playback output control to the power amplifiers.

I think I would start by 'scoping the outputs of those 2 modules in each channel and see what the signals look like.

chriswood1900 · 27th Aug 2018, 5:19 pm

I have a had the problem with low output a couple of times on Series 7 and traced it to the 1uf electrolytic C506 in the feed to the first transistor VT505, it seems to have insufficient bias to keep it working and fails over time. I usually change it for a non electrolytic and the problem goes away.
Good luck Chris

NorfolkDaveUK · 27th Aug 2018, 5:35 pm

Quote:

Originally Posted by TonyDuell

Now I've not started on my Ferrograph 722H yet, so I am working from the manual only. The service manual I have (on paper, it was given to me with the machine) has very clear circuit diagrams, but the scanned version I found has them as 4 overlapping sheets which I guess are not clear. Alas I don't have a larger-than-A4 scanner so I can't produce a better version from my manual.

The unit is quite modular. The signal from the replay head goes to the replay amplifer. The output of that goes to a preset level control and monitor switch to the meter/tone control board. Then to the main playback output control to the power amplifiers.

I think I would start by 'scoping the outputs of those 2 modules in each channel and see what the signals look like.

Thanks tony , I have a decent half track now so I`ll record a 10 min 10k signal i think . will make the whole thing a lot easier . I`ll get on with it in a bit and let you know how i get on thanks .

Quote:

Originally Posted by chriswood1900

I have a had the problem with low output a couple of times on Series 7 and traced it to the 1uf electrolytic C506 in the feed to the first transistor VT505, it seems to have insufficient bias to keep it working and fails over time. I usually change it for a non electrolytic and the problem goes away.
Good luck Chris

I`ll be re-capping it completely anyway so if that is the issue it`ll certainly be located for sure , the left side has no audio at all though so need to nail that down too . what did you put in place of the electro cap ? film ?

TonyDuell · 27th Aug 2018, 5:43 pm

I assume you know that there are 2 versions of the electronics, one has a 'Tape/Normal/Source' switch, the other a 'Tape/Source' switch.

If these are not in the Tape (or Normal if you have it) position then you will get no audio from the tape. Conversely, in the 'Source' (or 'Normal' and record mode I think) you can feed an input signal through the amplifier, bypassing the tape (and the replay pre-amp board). That might be useful for testing.

NorfolkDaveUK · 27th Aug 2018, 6:01 pm

Yeah thanks tony , I have the "2" position version . The switch is REALLY noisy , so i`m pretty sure the problem is in the early stages , the power amp is amplifying the grot in the switches just fine ..haha . I`ll be cleaning those out first of course just in case that`s the issue but I don`t think so I think its the pre or the eq (tone / meter) boards . Just recording a test signal now and I`ll get to work on it .

27th Aug 2018, 10:38 am	#1
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Ferrograph series 7 Grand Opening I`ve started a new thread because the other one was more about ferrograph v revox in the end soo ..lol To say I`m more that a little shocked to find what I have in side here is an understatement , I assumed because it had sat in the shed for 20+ years in the same spot and has stuff piled on it , got a bit damp I would find corrosion , rust critters etc in here , however ..........(see pics) So I guess we can draw from that that at least the case is a winner for this machine . . It had a few cobwebs , but don`t we all at our age .lol . I would call that a result , Now to make it work . .......... Attached Thumbnails

27th Aug 2018, 11:13 am	#2
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . Can anyone tell me if this has some kind of safety feature that stops you using it outside of the case ? Now its out nothing is working except for the power light . Could be related to the smoke of course ..lol Thanks Last edited by NorfolkDaveUK; 27th Aug 2018 at 11:18 am.

27th Aug 2018, 11:17 am	#3
terry123 Pentode Join Date: Jan 2004 Location: Rosyth, Fife, UK. Posts: 204	Re: Ferrograph series 7 Grand Opening . Have you put all the fuses back in after the cabinet removal? If so you may want to check that they are still intact and have not become detached inside the holder. Terry __________________ Terry Martini-Yates BVWS Committee Vice Chair

27th Aug 2018, 11:28 am	#4
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . It came out nicely without removing them bud. I checked them though and they are all ok . The last time I played with it , it started smoking just before I turned it off , so I`ll pull the power unit . I would have thought that came from the dirty great wire wound at the top there though. its covered in dust On a different note , this has some really weird wheels in it . I bought some of the originals to put in it but the ones in it are pale blue and rock hard . Now I though because they are rock hard they were borked , but the worked ok ? you know of these things ? Last edited by NorfolkDaveUK; 27th Aug 2018 at 11:41 am.

27th Aug 2018, 11:41 am	#5
terry123 Pentode Join Date: Jan 2004 Location: Rosyth, Fife, UK. Posts: 204	Re: Ferrograph series 7 Grand Opening . Hi sounds like they are some sort of past replacement. Terry __________________ Terry Martini-Yates BVWS Committee Vice Chair

27th Aug 2018, 11:51 am	#6
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . Yeah thats great because they haven`t melted all over the place they have just gone hard . They are 3 times thicker than the originals too . I think i`m going to have to replace them because being rock hard can`t be good for the other parts can it . (see pic) Terry do you have a schematic showing the voltages ? The one I have (hfe) doesn`t ..ta. Attached Thumbnails

27th Aug 2018, 12:25 pm	#7
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . Nevermind Terry i found it , the "tape in switch " needed a good clean . Works treat now , it needs a lot of cleaning but other than that i think its good to go pretty much

27th Aug 2018, 12:29 pm	#8
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . Does need a pinch roller if you can PM me a price please Terry . Cheers

27th Aug 2018, 12:56 pm	#9
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . You know I dont think these were designed to be soft at all . I think these are "goo busting" replacements . I`ve not heard of them at all , but these are definitely plastic and not rubber they are screwed to the brass wheel . The pinch roller is the same .. Attached Thumbnails

27th Aug 2018, 1:05 pm	#10
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Ferrograph series 7 Grand Opening . Good result Dave. I don't think mine has been in a shed so I will to take a look when I go North this week, after your positive experience I'm not clear about you just having a power light when you took it out of the case and then cleaning the "tape in" switch. Did you mean the deck was running but you couldn't record/playback Dave W Bexhill

27th Aug 2018, 1:11 pm	#11
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . No it was completely dead apart from the "reset" light . after moving the tensioner arm up and down a few times the light went out with the tensioner up and we were off . I dont know what to do about those wheels now . I think i`m going to put them back in after I clean up the motor shaft and see how they perform . I can imagine that when it gets hot in there they are going to soften up slightly and might well perform pretty well . we will see. Once I`ve done that I`m going to re-cap the amps and I`ll let you all know how its going this evening . Peace !

27th Aug 2018, 1:18 pm	#12
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Ferrograph series 7 Grand Opening . Oh right Dave. I thought that there must be a "missing link". It's similar to the tension piece on the Akai 4000 isn't it. That only comes into use on one position of the mains switch. Quite a few people used to post about that as it wasn't so obvious if you didn't have the Handbook! Dave

27th Aug 2018, 2:16 pm	#13
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . I knew it was there bud but it wasn`t working , it was filthy , so was activating when it felt like it ..lol A quick clean with some alcohol brought it into my way of thinking .lol

27th Aug 2018, 4:04 pm	#14
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . So after now playing with it a bit , I need some help . The output is right side only and VERY low . I have re-capped the amps on the power board assy , problem remains the same . Switch crackle is pretty loud though so i think the amps are ok so the signal is getting lost somewhere it seems . Can someone that knows the machine tell me where to trace the signal please . The schematic I have is awful . No VU action at all . The plastic wheels have GOT to go they make a HELL of a racket , its almost unbearable . Good idea for stopping the goo maybe . terrible for keeping the noise to a minimum . transport is now working , how much fun is the wind thing ..haha ... The audio that is playing (albeit really quietly ) sounds really clear and crisp . Just need more of it ! and on both sides !

27th Aug 2018, 5:14 pm	#15
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . OK i got the sequence , replay pre-amp , meter and tone then power amp . .... , there is no meter action at all so I think the issue is right back at the preamp stage so I`ll sort those out first !

27th Aug 2018, 5:19 pm	#16
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Ferrograph series 7 Grand Opening . Now I've not started on my Ferrograph 722H yet, so I am working from the manual only. The service manual I have (on paper, it was given to me with the machine) has very clear circuit diagrams, but the scanned version I found has them as 4 overlapping sheets which I guess are not clear. Alas I don't have a larger-than-A4 scanner so I can't produce a better version from my manual. The unit is quite modular. The signal from the replay head goes to the replay amplifer. The output of that goes to a preset level control and monitor switch to the meter/tone control board. Then to the main playback output control to the power amplifiers. I think I would start by 'scoping the outputs of those 2 modules in each channel and see what the signals look like.

27th Aug 2018, 5:19 pm	#17
chriswood1900 Octode Join Date: Jan 2007 Location: Dorridge, West Midlands, UK. Posts: 1,481	Re: Ferrograph series 7 Grand Opening . I have a had the problem with low output a couple of times on Series 7 and traced it to the 1uf electrolytic C506 in the feed to the first transistor VT505, it seems to have insufficient bias to keep it working and fails over time. I usually change it for a non electrolytic and the problem goes away. Good luck Chris

27th Aug 2018, 5:43 pm	#19
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Ferrograph series 7 Grand Opening . I assume you know that there are 2 versions of the electronics, one has a 'Tape/Normal/Source' switch, the other a 'Tape/Source' switch. If these are not in the Tape (or Normal if you have it) position then you will get no audio from the tape. Conversely, in the 'Source' (or 'Normal' and record mode I think) you can feed an input signal through the amplifier, bypassing the tape (and the replay pre-amp board). That might be useful for testing.

27th Aug 2018, 6:01 pm	#20
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: Ferrograph series 7 Grand Opening . Yeah thanks tony , I have the "2" position version . The switch is REALLY noisy , so i`m pretty sure the problem is in the early stages , the power amp is amplifying the grot in the switches just fine ..haha . I`ll be cleaning those out first of course just in case that`s the issue but I don`t think so I think its the pre or the eq (tone / meter) boards . Just recording a test signal now and I`ll get to work on it .