Author Topic: Tear down of a Clough Brengle Signal Gen from 1937  (Read 722 times)

0 Members and 1 Guest are viewing this topic.

Offline Radio Tech

  • Frequent Contributor
  • **
  • Posts: 904
  • Country: us
  • KC4UMO Buddy
    • Hobby Forum
Tear down of a Clough Brengle Signal Gen from 1937
« on: May 29, 2018, 10:50:35 am »

I wanted to tear this old unit down and see what it will take to get it back to standards of the day.

.
#166 Clough Brengle Model 110 Signal Gen Tear Down


Offline bsfeechannel

  • Regular Contributor
  • *
  • Posts: 180
  • Country: 00
Re: Tear down of a Clough Brengle Signal Gen from 1937
« Reply #1 on: May 30, 2018, 06:07:18 am »
I fell in love with that band switch.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 1546
  • Country: au
Re: Tear down of a Clough Brengle Signal Gen from 1937
« Reply #2 on: June 02, 2018, 09:07:21 am »

Mr. Radio Tech, were you using an isolation transformer/variac/dim bulb chain to power that lovely DUT?

If not, I cordially suggest to please source something asap,

lest unwanted zaps ruin your day and test gear big time  :o
 

Online vk6zgo

  • Super Contributor
  • ***
  • Posts: 4175
  • Country: au
Re: Tear down of a Clough Brengle Signal Gen from 1937
« Reply #3 on: June 02, 2018, 11:17:47 pm »

Mr. Radio Tech, were you using an isolation transformer/variac/dim bulb chain to power that lovely DUT? I

If not, I cordially suggest to please source something asap,

lest unwanted zaps ruin your day and test gear big time  :o

Maybe a variac or dim bulb, but there should be no need for an isolation transformer.
Pre WW2 US made equipment, especially test gear, did not use transformerless construction.
That sort of thing was used for the postwar "All American Five" receivers as a cost cutting measure.

If you look closely at the quite quick view of the schematic, you will see a power transformer with
centre tapped secondary feeding a rectifier tube in a classic full wave rectifier circuit.
 

Offline Radio Tech

  • Frequent Contributor
  • **
  • Posts: 904
  • Country: us
  • KC4UMO Buddy
    • Hobby Forum
Re: Tear down of a Clough Brengle Signal Gen from 1937
« Reply #4 on: June 02, 2018, 11:58:20 pm »
I fell in love with that band switch.

Yes it is a thing of beauty. Very clever design. Sure beats a wafer switch that could fail.

Offline Radio Tech

  • Frequent Contributor
  • **
  • Posts: 904
  • Country: us
  • KC4UMO Buddy
    • Hobby Forum
Re: Tear down of a Clough Brengle Signal Gen from 1937
« Reply #5 on: June 03, 2018, 12:03:57 am »

Mr. Radio Tech, were you using an isolation transformer/variac/dim bulb chain to power that lovely DUT?

If not, I cordially suggest to please source something asap,

lest unwanted zaps ruin your day and test gear big time  :o

The unit was brought to life on a current limiting isolation device at first power up.
I did not use an isolation transformer for this test.  I wanted the viewers to see the full effect of faulty equipment so they would know the dangers.  So hopefully if they watch this video they will see the hazards with this older gear.

As mentioned already (Thanks vk6zgo)  this unit have a real transformer unlike the proceeding "All American Five" units types.
The chassis is hot due to failing capacitors that is leaking AC to the chassis.

Offline Radio Tech

  • Frequent Contributor
  • **
  • Posts: 904
  • Country: us
  • KC4UMO Buddy
    • Hobby Forum
Re: Tear down of a Clough Brengle Signal Gen from 1937
« Reply #6 on: June 03, 2018, 12:04:46 am »

Mr. Radio Tech, were you using an isolation transformer/variac/dim bulb chain to power that lovely DUT? I

If not, I cordially suggest to please source something asap,

lest unwanted zaps ruin your day and test gear big time  :o

Maybe a variac or dim bulb, but there should be no need for an isolation transformer.
Pre WW2 US made equipment, especially test gear, did not use transformerless construction.
That sort of thing was used for the postwar "All American Five" receivers as a cost cutting measure.

If you look closely at the quite quick view of the schematic, you will see a power transformer with
centre tapped secondary feeding a rectifier tube in a classic full wave rectifier circuit.


 :-+
Spot on


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf