• Country
• Great Britain (UK)

• Manufacturer / Brand
• Homebrew - RECENT but NOT Replica GB

• Year
• 2018/2018

• Category
• Service- or Lab Equipment

• Radiomuseum.org ID
• 305457

Click on the schematic thumbnail to request the schematic as a free document.

• Number of Tubes
• 2

• Valves / Tubes
• 1Б10-17 6Ц4П 4Ц14С

• Wave bands
• - without

• Power type and voltage
• Alternating Current supply (AC) / 240 Volt

• Loudspeaker
• - - No sound reproduction output.

• Material
• Plastics (no bakelite or catalin)

• from Radiomuseum.org
• Model: 1B10-17 Diagnostics-Kit [V1] - Homebrew - RECENT but NOT

• Shape
• Tablemodel, with any shape - general.

• Dimensions (WHD)
• 242 x 124 x 205 mm / 9.5 x 4.9 x 8.1 inch

• Notes

• I've created a precise easy-to-read ammeter specifically for the 1B10-17 Barretter/Iron-Hydrogen resistor/Ballast tube. It measures the current through the 1B10-17 at 10V and 17V. Problem with other moving-coil and even digital ammeters is most of them are only accurate or easy to read upto 2 significant figures when it comes to currents of 1A and above, and AC ones are especially bad. This device has a very large high-quality analog meter and the way the circuit is set it shows 21uA when the current is exactly 1000mA. With each 10mA of change in filament current, the meter moves the pointer by 1uA division. This makes it very easy to read, just power the circuit up, wait about 20 seconds for it to fully settle and then just count in 10mA per division. The amplification factor with the current setup is 4.76%. A normal meter might experience problems from the in-rush current surge, but this device can handle it easily and the pointer on the meter never slams against the end, which could have caused future inaccuracy. The circuit is also designed to make the surge on all the tubes minimal. The 1B10-17 supplies current to the filament of the 4Ц14С which is a saturation diode used for controlling circuits (not a noise diode) and with a small change in the filament current, there is a significant change in anode current. The 4Ц14С needs more than 1A of current, at max power it uses 1.75A on average. The potentiometer for the extra filament supply from another transformer is set to a certain value and even a 1 degree of movement will completely change the ballance and accuracy, I used an old NOS 1958 RAF 5 Ohm Colvern Wirewound. For the 1B10-17 I used an old 1920s-30s B4 base in which the Barretter slides in and out very easily. All the resistors are upto 10 times higher W-rating than needed for minimal resistance drift. The anode supply is pretty simple and self-explanatory. Thanks to 4Ц14С' non-linear saturated emission, the capacitor can be very small, as ripple doesn't affect anode current until 25V, but I decided to make ripple minimal by having a large capacitor after the 6Ц4П. 

• Net weight (2.2 lb = 1 kg)
• 7.5 kg / 16 lb 8.3 oz (16.52 lb)

• Author
• Model page created by Yaroslav Voronov. See "Data change" for further contributors.

• Other Models

• Here you find 18 models, 5 with images and 3 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Homebrew - RECENT but NOT Replica GB