1930's Ferguson radio - UK Vintage Radio Repair and Restoration Discussion Forum

vinrads · 23rd May 2024, 4:43 pm

This radio was gifted to me by John (old John) after replacing all the paper capacitors, output TX and HT choke/speaker energising coil the set came to life. At this time I didn't have a circuit, which left me wondering what these strange looking things were which didn't read anything. Having then received a service manual, a big thanks to Dave (G6ONEDave) I discovered they were low voltage cells. Note this radio was built in 1938. I have fitted two E cig batteries and a resistor to obtain 5.5 volts. My next job is to re align the set.

Mick.

Station X · 23rd May 2024, 6:12 pm

Grid bias batteries which don't have to supply any current.

60 oldjohn · 23rd May 2024, 6:26 pm

Hi Mick, Pleased you are making progress with the radio. Strange the Grid Bias battery, I had an Ambassador radio that used a D cell (HP2) Grid Bias supply. I suppose it would give the repair shop a job when it failed possibly many years ahead (Shelf Life) as no current would ever be used as long as the capacitors were in good condition.

John.

Silicon · 24th May 2024, 10:00 am

Those Mallory Bias Cells were available in 1 Volt and 1.25 Volt versions.

Some restorers inject a little water into the cells with a syringe to re-activate them.

Nickthedentist · 24th May 2024, 10:43 am

That's a new one on me. Heard of them but never come across a set which employs one.

What's the Ferguson's model, Mick? The only one I have here is the 501AC from 1937.

vinrads · 24th May 2024, 11:55 am

Hi Nick it's a Ferguson 773 motor tuned , 5.5 volts is applied to a 6j7 which acts on the osc to keep stability when on auto tune . Mick.

23rd May 2024, 4:43 pm	#1
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,940	1930's Ferguson radio This radio was gifted to me by John (old John) after replacing all the paper capacitors, output TX and HT choke/speaker energising coil the set came to life. At this time I didn't have a circuit, which left me wondering what these strange looking things were which didn't read anything. Having then received a service manual, a big thanks to Dave (G6ONEDave) I discovered they were low voltage cells. Note this radio was built in 1938. I have fitted two E cig batteries and a resistor to obtain 5.5 volts. My next job is to re align the set. Mick. Attached Thumbnails

23rd May 2024, 6:12 pm	#2
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 22,313	Re: 1930's Ferguson radio Grid bias batteries which don't have to supply any current. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

23rd May 2024, 6:26 pm	#3
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 4,238	Re: 1930'S Ferguson radio Hi Mick, Pleased you are making progress with the radio. Strange the Grid Bias battery, I had an Ambassador radio that used a D cell (HP2) Grid Bias supply. I suppose it would give the repair shop a job when it failed possibly many years ahead (Shelf Life) as no current would ever be used as long as the capacitors were in good condition. John. __________________ My favourite text message "I'll be there in five minutes, if not read again" Last edited by 60 oldjohn; 23rd May 2024 at 6:32 pm.

24th May 2024, 10:00 am	#4
Silicon Nonode Join Date: Jun 2007 Location: Coulsdon, London, UK. Posts: 2,467	Re: 1930's Ferguson radio Those Mallory Bias Cells were available in 1 Volt and 1.25 Volt versions. Some restorers inject a little water into the cells with a syringe to re-activate them.

24th May 2024, 10:43 am	#5
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 18,695	Re: 1930's Ferguson radio That's a new one on me. Heard of them but never come across a set which employs one. What's the Ferguson's model, Mick? The only one I have here is the 501AC from 1937.

24th May 2024, 11:55 am	#6
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,940	Re: 1930's Ferguson radio Hi Nick it's a Ferguson 773 motor tuned , 5.5 volts is applied to a 6j7 which acts on the osc to keep stability when on auto tune . Mick.