The clocks have gone back ...

Vipersan

Vipersan

Emmett Browns Ghost
Staff member
Messages
10,914
My Satellite Setup
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
My Location
UK
...but a long way back in my shop..
Back to the early nineteen seventies in fact ..
Nelson brought me a Ferrograph Amp for repair ...
In truth I have worked on this amp before and this is it's second visit ..
This time I decided not to search for the crackling noise on one of the channels ..as this would take a long time ..and prove less economical than to rebuild the channel ..
So ..I finally managed to get the schematic and board layout ..so the next step was to source the components ..
roughly 100 ..
A mix of carbon resistors ..transistors and capacitors ..
Well ..few if any original philips caps still existed so originals where possible and modern equivalents if not..
These I gathered from various UK suppliers..
Next the half watt carbon resistors ..
The most economical way to approach this was to buy a 'kit' containing about 10 of each need value ..plus many I didn't need ..
Sourced from China ...as greedy UK suppliers wanted about 4 times the price for the same components.
Finally Transistors..
Luckilly the output transistors could be reused as these would be almost impossible to source ...
which is not to say the others were easy ..
Finally found someone with 'old' new stock in Holland who was prepared to ship me what I needed ..

Having got everything together ...and armed with the schematic I set about rebuilding the amp channel driver board ..
Completed it yesterday ...and on powering up was rewarded with ...errr ..
Nothing .
Turned out the test speaker I had connected to this channel was open circuit ...so borrowed the speaker off the working channel ..
To say that the sound quality is anything other than superb would not be doing it justice..
They certainly knew how to build an amp back then.
Anyone familiar with the Ferrograph name knows it was ascociated with quality ...and the BBC ..
Not reassembled yet ..but another success in the making..
rgds
Evan
Ferrograph Amp.jpg
 
Last edited:
Lazarus

Lazarus

Tout Rond Bon Oeuf
Staff member
Messages
25,527
My Satellite Setup
80cm Motorised.
Several small Dishes.
Much else.
My Location
North York Moors
And all you need do now is take a Charge over Nelson's home to cover the cost!

Seriously, well done. Most impressed :-applause
 
sonnetpete

sonnetpete

Grumpy Old Moderator
Staff member
Messages
7,306
My Satellite Setup
Laminas 1.2M fibre dish with an IBU, on a Clarke Tech USALS motor, covering 57E - 24.5W to an Octagon SX88. Displayed on a 20" Dyon LED TV.

Seperate 80 cm dish on 28E with a Humax Freesat for SWMBO.
Free Sat V8 meter. Sony Bravia 46" LCD, Sony BluRay and Home Cinema.
My Location
Normandy, France
Really impressed VS. Weren't Ferrograph best known for their high quality (studio?) reel to reel tape recorders?
 
Vipersan

Vipersan

Emmett Browns Ghost
Staff member
Messages
10,914
My Satellite Setup
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
My Location
UK
Really impressed VS. Weren't Ferrograph best known for their high quality (studio?) reel to reel tape recorders?
Indeed they were Pete ..
The ascociation between Ferrograph the BBC ..and QUALITY was well known at that time ..
Magnetic Tape ..Reel to Reel being foremost I think ..
 
Vipersan

Vipersan

Emmett Browns Ghost
Staff member
Messages
10,914
My Satellite Setup
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
My Location
UK
Vipersan

Vipersan

Emmett Browns Ghost
Staff member
Messages
10,914
My Satellite Setup
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
My Location
UK
Apparently this amp was first advertised for sale in 1969 ...
Amazing !
 
A

Archive7

Guest
BTW I have a stock of several standard carbon film resistors (Philips) 1/4 watt somewhere from an old project. Let me know if you need any specific values in the future and I will check if I have them.
 
Vipersan

Vipersan

Emmett Browns Ghost
Staff member
Messages
10,914
My Satellite Setup
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
My Location
UK
BTW I have a stock of several standard carbon film resistors (Philips) 1/4 watt somewhere from an old project. Let me know if you need any specific values in the future and I will check if I have them.
Thanks mate ..
I already had several of the required values in 1/4 watt carbon ...
..but many of the ones in the amp were rated 1/2 watt ...and I had very few of these ..as they aren't used in TVs these days..
99.9% SMD..
cest la vie
 
hvdh

hvdh

Specialist Contributor
Messages
1,959
My Satellite Setup
Dr.HD F16, TBS 6925, T-55, Laminas 120 cm
My Location
Oss, NL (5.5°E 51.8°N)
Vipersan

Vipersan

Emmett Browns Ghost
Staff member
Messages
10,914
My Satellite Setup
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
My Location
UK
Just checked on the auctioned amp on fleabay ..
still 6 days to run ...and already at £99.99
Better look after yours Nelson ..
lol
 
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jeallen01

jeallen01

Specialist Contributor
Messages
3,787
My Satellite Setup
See Signature
My Location
Somewhere in England (possibly?)!
Memories! - I kinda lusted after something like that Ferrograph amp in the early '70s but most certainly could not afford it (finally bought a relatively good, and much cheaper, Sansui amp - "2020" IIRC but I am probably wrong - but it was pretty good as far as I was concerned, on credit card (my first EVER cc purchase, and it then took me 6 months to pay that off :) )). Seriously, Ferrograph was a very respected manufacturer then - great pity that it then went the way it did
 
Vipersan

Vipersan

Emmett Browns Ghost
Staff member
Messages
10,914
My Satellite Setup
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
My Location
UK
Well ..If repairing this amp was a trip back in time for me ..
I've just watched the first night of Television ...
I swear I just time slipped some more ..
Absolutely incredible that in 80 years we went from flying spots with 200 line scanning to OLED and 3D /4K ..
Mind blowing really ..
Anyone else make the trip ??
rgds
VS
BBC to recreate first night of programming, 80 years on
 
nelson_b

nelson_b

Contributor
Messages
1,655
My Satellite Setup
Strong 4375 driving 1.8 C.M. offset + Inverto Black Ultra twin + BSC 421 and Zinwell C band l.n.b.,s - DR HD F15 - TM5302 and Skybox/Openbox M3 - HD receivers.+ other dishes in use - 2.4 CM offset - Alcoa 1.8 P.F. - C.M. 120.
My Location
north west yorkshire
The old Ferrograph amp is back in it position here at my place, and performing brilliantly.
(thanks very much Evan) :)
And its paired up this time with some speakers of the same (1969) vintage.
Celestion Ditton 15

ditton 15.jpg
 
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