AVO Valve Characteristic Meter Mark IV

AVO Valve Tester Mk 4

My Main Valve(tube) tester , It been a good old friend for a number of years

It was missing its Vset ~ knob when I had it and 

years later I have never needed to adjust the V set ~

This can test all types of normal valves , Diodes , Triodes , Pentodes, Tetrodes, indirect or directly heated.

Tests:

Inter electrode leakage/shorts

Mutual conductance

Plot Ia/Vg at a range of parameters

this machine is an excellent compliment to any workshop

Lafayette HA55A, Air band Receiver

                                                                     Lafayette HA55A

A 1960’s Air band receiver

This was one of my few encounters with a Nuvistor 6CW4 in the front end

The set now works however I have noted a few issues with regards to its original specification

Tuning range 108 –136 Mhz

See below

Sensitivity 4uV

Even with a Nuvistor the 4uV is quite poor

Image ratio 40dB

Actually the set suffers from poor image rejection and one can receive a range of Band 2 Broadcast stations which can swamp the receiver

The set does use a strange selection of valves even for the 1960’s,

Apart from the above negatives the radio receives Birmingham very well

HA55A Circuit Schematic 

HA55A Alignment 

Hope this helps

 

KW Radio On Air Event

Do you own a KW radio ?

KW 76 ,KW Atlanta, KW 204, KW Valiant, KW Viceroy, KW201, KW Vespa, KW2000, KW2000A KW2000B

Get It on the Air

KW Weekend 5^th- 6^th January 2014

 

This is one of my collection a KW2000's acquired in the late 1990's in a very sad state .

All the Hunts have been changed, the PSU electrolytic's have also gone and a few resistors changed

then a full realignment 

I never fully addressed the aesthetics, as the tuning escutcheon plate is from a 2000a

and I never quite got around to changing the 1/4” Microphone jack socket back to a DIN

The mechanical Filter did not require any work at all

A superb radio of British manufacture from the early 1960's giving excellent audio

Spark Transmitter

This is one of my oldest Transmitters

a home built sparker dated 1911 

I believe was a Gammage's of London set 

and No , I have not fired it up 

AVO Universal Measuring Bridge Type 1

AVO Universal Measuring Bridge Type 1

Bench mounted Measuring Bridge

Manufacturer :- Automatic Coil Winder and Electrical Equipment Co, Douglas Street, London

Brand :-AVO

Power :- External Main supply 240VAC

Ranges:-

Resistance:- 6 Ranges 0.1Ώ to 1000MΏ Accuracy ±1% at mid scale

Capacitance:- 6 Ranges 1pF to 1000µF Accuracy ±1% at mid scale

Inductance:- 6 Ranges 1mH to 1000H Accuracy ±2% at mid scale

Fully functional and used

Source:- My own collection
Donated by the son of a deceased colleague

AVO Signal generator Type T.F.M.

AVO Signal generator Type TFM

Bench mounted Signal generator

Manufacturer :- Automatic Coil Winder and Electrical Equipment Co, Douglas Street, London

Brand :-AVO

Power :- External Main supply 240VAC

Ranges:- 8 Frequency ranges

Modulation AM and FM

Approx 8Mhz to 200Mhz higher on harmonics

Fully functional and used

Source:- My own collection
Donated by the son of a deceased colleague

Micronta (Tandy) Digital Multimeter Model 22-198A

 

 

Micronta (Tandy) Digital Multimeter Model 22-198A

A medium sized hand held/bench Digital multimeter

Manufacturer:- Not Known, Custom Made for (Radio shack, Tandy UK )

Brand:- Micronta

Power :- Internal dry battery 9V, PP3 type

Sensitivity:DC or AC:1.5MΏ /volt

Ranges:-

  DC Voltage:0- 1000 volts
  AC Voltage:0-1000 volts
  DC Current:0- 2A
  Resistance: 0-20Meg 
  

Fully functional, Not used, retained for curiosity

Source:- My own collection
Donated by the son of a deceased colleague 

 

Micronta (Tandy) Multimeter Model 22-204B

Micronta (Tandy) Multimeter Model 22-204B

A medium sized hand held/bench analogue multimeter

Manufacturer:- Not Known, Custom Made for (Radio shack, Tandy UK )

Brand:- Micronta

Power :- Internal dry batteries 1.5V AA

Sensitivity:DC: 50,000Ώ /volt or 25,000Ώ /volt    AC:10,000Ώ /volt or 5,000Ώ /volt

Ranges:-

  DC Voltage:0-125mV - 1000 volts
  AC Voltage:0-1000 volts
  DC Current:  0-25microA -10A
  Resistance: 0-20Meg 
  Decibels:  -20 to + 62 

Fully functional, Not used, retained for curiosity

Source:- My own collection
Donated by the son of a deceased colleague 

 

AVO Multimeter Model 72

AVO Multimeter Model 72

A small hand held analogue multimeter

Manufacturer :- Automatic Coil Winder and Electrical Equipment Co, Douglas Street, London

Brand :-AVO

Power :- Internal dry batteries 1.5V AA and 15 V

Sensitivity:- DC 20,000 ohm/V & AC 1000 ohm/V.

Ranges:- DC: 0-1000 Volts AC: 0-1000 Volts ; Ohms: Ώx1- Ώx100 - Ώx10k

DC Current 0,05-1000 mA.

Fully functional, Not used, retained for curiosity

Source:- My own collection
Donated by retired Electrician

The Seesure Transistor tester

The Seesure Transistor tester

I don’t know a lot about this it runs from an external low voltage DC supply

and the control adjusted till the lamp changes then the hfe is read from the scale

Power:- External 9V

measuring:- hfe 5- 500 ?

Type:-  both NPN & PNP transistors

Does work ? Not used, retained for curiosity

Source:- My own collection 
Purchased  from Telford Rally 1980's

Jay-Jay, Inductance box

Jay-Jay, Inductance box 

 

Manufacturer:- Educational Measurements Ltd, Warsash, Southampton

Brand :- Jay-Jay Instruments

type:- L3

Description:- 3 x 10 position Inductance knobs (Inductance in Henrys)

x 10^-1 @ 30mA

x 10^-2 @ 50mA

x 10^-3 @ 70mA

still in use for Calibration and design of equipment

Source:- My own collection
Purchased  from Wythall Rally late 1990's

Jay-Jay, Resistance decade box

Jay-Jay, Resistance decade box

Manufacturer:- Educational Measurements Ltd, Bitterne , Southampton

Brand :- Jay-Jay Instruments

type:- 1

Description:- 4 x 10 position resistance knobs

Ω x 10000@ 7mA

Ω x 1000 @20mA

Ω x100 @70mA

Ω x10 @100ma

still in use for Calibration of equipment

Source:- My own collection
Purchased  from Wythall Rally late 1990's

Micronta Signal Injector SI-100

Tandy (Micronta) Signal Injector 

 

Use:- hand held unit for injecting test signals into circuits

Power:-   2 x AA cells 

Output:- Wide frequency output range from Audio to high RF on harmonics 

 

Now still used for quickness

Source:- My own collection 
Purchased  from Tandy own store in Wednesbury,  1980's

Eagle Transistor tester Model TT145

Eagle Transistor tester TT145

For testing Transistors both PNP & NPN transistors, measuring current gain, Alpha, Beta & Ico

may also be used to test diodes, forward & reverse

better suited to long lead devices,

Power:- internal 9V battery, PP3 range 

Internal :- resistor bank with meter and appropriate switching

Test connection:- via 4mm plug lead set or “push in” type connector,

Made by:- TTC Quality Electronics

Country:- Japan  late 60;s early 70's

Product manual

 

Brand:-also branded as TTC C3022 & Alcron 22

Now modified for testing SMT transistors

Source:- My own collection 
Purchased  from Drayton Manor Rally 1980's

Eagle K 200 FET Vom

Eagle K200 (Field effect transistor) FET VOM

FET VOM. K-200 - Kyoritsu, Tokyo

Ranges:
DC volts 0–1000 V;
Direct current : 0–300 µA, 0–300 mA;
AC voltage: 0–1000 V;
Max 0–2800 V;

dB -25,2 +62 dB ,      0 dB = 1 mW into 600 Ω 

Alternating current (AC ): 0–300 µA, 0–300 mA;
:Resistance measurement 0–500 MΩ 7 Ranges

Brand:- Eagle also branded Kyoritsu. Both marked with model number K-200

These were made in Japan around 1970

condition :-Working fine little used 
 

Source:- My own collection 
 Purchased  from Wythall Rally  00's

Eagle SG70 Signal Generator

Eagle SG70 Signal Generator

  

Up to 500 MHz in six bands, higher with harmonics

Facility for internal or external modulation

Facility for external Crystal

220 - 240 Volts AC supply.

Two valves 12BH7 Similar to EEC81 series) 6AR5 (Similar to 6AQ5)

HT rectifier is a Silicon Rectifier.,

These were made in Japan around 1970. 

I now use this just for testing Crystals 

Circuit for  the Eagle SG70

Source:- My own collection 
 Purchased  from Wythall Rally  00's