TMK 700 Multimeter - UK Vintage Radio Repair and Restoration Discussion Forum

Chryseus · 21st Jun 2013, 12:45 pm

Hey guys I just picked up a very good condition TMK 700 from ebay quite cheaply, there is nothing wrong with it except some missing batteries for the Ohm's measurement which I hope you guys can help me out with.
Certainly I could cheat and add a standard battery holder since there is plenty of spare room inside but I'd rather keep it original if possible.
The schematic I got hold of shows two 1.5V batteries but the radio museum page for the TMK 700 indicates 1.5V and 15V so I don't know what to think.

Here is the schematic for it (sorry for low quality, best I could find
http://u.cubeupload.com/Chryseus/83dg6N.png

And a look at the battery holder base
http://u.cubeupload.com/Chryseus/tFgf84.jpg

The dimensions of the battery holders are:
Diameter = 19mm
Height = 34mm

and

Diameter = 26mm
Height = 45mm

WME_bill · 21st Jun 2013, 2:32 pm

TMK700. I had a TMK500 for many years. Batteries were 1.5V for the Lower Ohms ranges, and 15V for the High Ohms. I would expect the same for your model, as 15v will be needed to drive the meter full scale through the range resistors. wme_bill

Chryseus · 21st Jun 2013, 3:59 pm

Quote:

Originally Posted by WME_bill

TMK700. I had a TMK500 for many years. Batteries were 1.5V for the Lower Ohms ranges, and 15V for the High Ohms. I would expect the same for your model, as 15v will be needed to drive the meter full scale through the range resistors. wme_bill

Thanks for the reply, I'll order up some lithium cells to replace the 15V.

camallison · 21st Jun 2013, 6:29 pm

Cor - that takes me back - I had one of those in the early 70s! Can't remember where it went. Good little meter that took a lot of rough treatment.

Colin

21st Jun 2013, 12:45 pm	#1
Chryseus Retired Dormant Member Join Date: Jul 2012 Location: Romney Marsh, Kent, UK Posts: 13	TMK 700 Multimeter Hey guys I just picked up a very good condition TMK 700 from ebay quite cheaply, there is nothing wrong with it except some missing batteries for the Ohm's measurement which I hope you guys can help me out with. Certainly I could cheat and add a standard battery holder since there is plenty of spare room inside but I'd rather keep it original if possible. The schematic I got hold of shows two 1.5V batteries but the radio museum page for the TMK 700 indicates 1.5V and 15V so I don't know what to think. Here is the schematic for it (sorry for low quality, best I could find http://u.cubeupload.com/Chryseus/83dg6N.png And a look at the battery holder base http://u.cubeupload.com/Chryseus/tFgf84.jpg The dimensions of the battery holders are: Diameter = 19mm Height = 34mm and Diameter = 26mm Height = 45mm

21st Jun 2013, 2:32 pm	#2
WME_bill Octode Join Date: Oct 2007 Location: Exeter, Devon, UK. Posts: 1,554	Re: TMK 700 Multimeter TMK700. I had a TMK500 for many years. Batteries were 1.5V for the Lower Ohms ranges, and 15V for the High Ohms. I would expect the same for your model, as 15v will be needed to drive the meter full scale through the range resistors. wme_bill

21st Jun 2013, 6:29 pm	#4
camallison Heptode Join Date: Feb 2013 Location: Yarm, North Yorkshire, UK. Posts: 535	Re: TMK 700 Multimeter Cor - that takes me back - I had one of those in the early 70s! Can't remember where it went. Good little meter that took a lot of rough treatment. Colin