[TMC] Directional Coupler Advice/Parts needed

[Roy Morgan]

TMC folks,

I got this request for help from a UK fellow on the Glowbugs list, and offered to forward his request to the TMC list:

It appears that he has an SWR-1K SWR indicator system, and the directional coupler has suffered a disaster (the cat knocked it off his bench and it broke!).  He’d like to find a replacement, or short of that may attempt a reconstruction of the coupler module.


From the manual on John Poulton’s collection:
http://www.virhistory.com/tmc/tmc_pages/tmc_manuals/manuals_db/swr/tm_swr-1k_2_17_73.pdf

It seems that the module is the DC-301 directional coupler known as the CU-2.  None of the parts in the thing seem to be unusual, but altogether it would be a daunting thing to reconstruct.  It’s not quite clear whether what’s broken is the whole DC-301/CU-2 assembly or just what might be the critical R301, a 0.6 ohm 40 watt resistor.

The manual states:  "CU-2 Coupler Assembly is replaced as a unit.  It requires precise alignment at the factory before use … "

Any advice or help in finding a replacement would be most appreciated.


Begin forwarded message:

> From: CLIVE COLLINS <dartaviation at btopenworld.com>
> Subject: [Glowbugs] Technical Materiel Company products information
> Date: January 15, 2016 at 11:34:43 AM EST
> To: Glowbugs <tetrode at googlegroups.com>
> Reply-To: CLIVE COLLINS <dartaviation at btopenworld.com>
> Delivered-To: k1lky68 at gmail.com 

> Good day gentlemen,
> Is there anyone out there who is a specialist in TMC equipment please. I need some information on their VSWR indicator that was fitted to the one kilowatt  linear please. The dtector eement in mine has suffered from a mechanical shock and I suspect that the  key element will need to be replaced as it appears to be formed from glass
> Thanks in advance,
> Regards
> Clive GW3WEQ North Wales Coast UK 

Later he sent me this:

On Jan 27, 2016, at 11:01 AM, CLIVE COLLINS <dartaviation at btopenworld.com> wrote:

> Good day Roy,
> I would be most grateful for any help on this problem like through the TMC network.
...
> With regard to the VSWR device.
> The tube in question is made of glass and is inserted inside the detector assembly to contain certain (as yet) unknown components that are part of the VSWR detector arrangement. I am fairly sure I can fabricate such a tube in copper as the glass one has a copper sputtering coating on the outside that as far as I can see is only a grounding arrangement but......?
> 
> This unit is the heart of the one kilowatt VSWR indicator that produces an output to the crossed needles display meters showing forward and backward VSWR and is so helpful in setting out put from a transmitter to optimum.
> I look forward to you comments.
> Kindest regards
> 
> Clive GW3WEQ North Wales Coast UK




Roy

Roy Morgan
k1lky68 at gmail.com
K1LKY Since 1958