Collins 270G Speaker

 

26 February 2024 - Picked this up at the Dalton hamfest this past weekend for $100.  This will match my 75A-3 receiver.

Heathkit IT-12 Signal Tracer

 

26 February 2024 - Got this assembled - now to test it.

14 February 2024 - Been pretty busy with work lately, but did manage to get some more done on this project over the past few days.

5 February - There is a 220v transformer that was available in the IT-12 and that's what I have in the IT-12 I acquired - the part number is below.

• P/N:       54-64-24  
• Desc.:     Power Transformer (P: 110/220V; S: 117V@45mA, 12.6V@1A)  
• Used in:  IT-12, IT-12E

4 February 2024 - Below is the IT-12 schematic.

3 February 2024 Update - Cleaned up the tube sockets and some other solder points more and checked the switches orientation  - as suspected they were backwards and I removed and reinstalled them in the correct position.  Also started working on cleanup of the transformer wiring and discovered the transformer has an additional set of wires on the primary - was this for 220v hookup?

3 February 2024 - More desoldering work to get ready for the rebuild.  Installed the capacitor from the rebuild kit yesterday.

1 February 2024 - Started work on rebuilding this - it's in rough shape inside - someone must have restored it but they did a terrible job - transformer lines cut and spliced and they used electrical tape to insulate the splices.  Also found one resistor not connected.  Removed most components and used my desoldering iron to clean up the tube and terminal strip contacts.  These are pictures before I started the work.

31 January 2024 - Additional testing and it's only working on audio - I did some checks and it looks like the rebuild kit should fix it.  Hopefully the transformer is OK.

29 January 2024 - Got this back on the bench yesterday - I added the ground wire and that resolved the hum issue and it's picking up the signal now from myAWG.  The eye tube might need replacing but I will explore this more as time permits.

28 January 2024 - Picked this up earlier in the week and got it on the bench for an initial checkout.  All tubes tested good - I ordered a capacitor rebuild kit which also includes all diodes, resistors and capacitors used in this kit.  There is a bad hum on this and it's not picking up a signal as expected, so I believe it has something out of tolerance.