UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Hammarlund HQ-180A I.F. Help Sought

IsquaredR · 7th Jan 2020, 3:56 am

Hello Al and thank you for your suggestion.

I have measured the resistance between all of T3's pins and will delineate them as per the letters on my photograph that is attached to my original post. The resistances are as follows:
A to B: Infinity
A to C: Infinity
A to D: 7.5 ohms
A to E: Infinity
B to C: Infinity*
B to D: Infinity*
B to E: Infinity*
C to E: 8.2 ohms
D to C: 3.5 ohms
D to E: 2.4 ohms

* The "B" pin is the pesky one that appears to NOT be connected to anything internally so obviously the resistance is whatever the ether will bear.

Finding a good clear schematic of the HQ-180A on the Internet is difficult so I scanned
the schematic from my original manual. Due to the size I uploaded it to the following links:

****************/K2swJDW
****************/WkPyFdV
****************/qrGJ2y3

I provided a scan of the left side, right side and a composite of both sides put together. Unfortunately the left side view cropped a little of the far left and I will try to rescan it when I am near a scanner tomorrow.

Appreciate any and all help.

7th Jan 2020, 3:56 am	#3
IsquaredR Tetrode Join Date: Apr 2017 Location: Minocqua, Wisconsin, USA. Posts: 86	Re: Hammarlund HQ-180A I.F. Help Sought Hello Al and thank you for your suggestion. I have measured the resistance between all of T3's pins and will delineate them as per the letters on my photograph that is attached to my original post. The resistances are as follows: A to B: Infinity A to C: Infinity A to D: 7.5 ohms A to E: Infinity B to C: Infinity* B to D: Infinity* B to E: Infinity* C to E: 8.2 ohms D to C: 3.5 ohms D to E: 2.4 ohms * The "B" pin is the pesky one that appears to NOT be connected to anything internally so obviously the resistance is whatever the ether will bear. Finding a good clear schematic of the HQ-180A on the Internet is difficult so I scanned the schematic from my original manual. Due to the size I uploaded it to the following links: **************/K2swJDW ************/WkPyFdV **************/qrGJ2y3 I provided a scan of the left side, right side and a composite of both sides put together. Unfortunately the left side view cropped a little of the far left and I will try to rescan it when I am near a scanner tomorrow. Appreciate any and all help.