VK Logger Ham Radio Forum Archive

Hello,
I have been eyeing off some of the junior TOHTSU relays (Tohtsu CX-140N SPDT N Type Coaxial Relay) for a couple of amplifier projects for the input path only. These junior version have a single type N on the common port and then two spots to push in a cable for N/O and N/C thus reducing the overall cost and the connector count and size taken inside the case.

http://www.tohtsu.com/shouhin.holder/CX-140D.html

My dilemma is that RG-188 is not a cable I have been able to source in VK and I am looking for a main stream equivalent, which seemed to be RG-316 but each time I look at a data sheet for this cable type I get conflicting answers. The TOHTSU relays require the centre of the coax to be solid (common enough I thought) but I now have four different data sheets for RG-316 and they alternate between saying is solid, stranded and in the case of another it just says its silver plated copper over steel.

Do any of the forum members have any real world experience with RG-188 and or RG-316 coax cables? Maybe you can put me out of my misery and give me the real answer

http://www.pasternack.com/images/Produc ... 188A-U.pdf

Nice cad drawing of 188

Friday, February 3, 2012




RG-316, RG-174, RG-188, Coaxial Cable-- Which One?

What Frequency Is the cable used?


What are the different parameters for a coaxial cable?
Frequency response:


Type RG-316 Temp -70C-+200 Jacket FEP Dielectric PTFE

RG-174 -50C+85C PVC Dielectric Polyethylene

RG-188 -200C +250C PTFE Dielectric PTFE

Shield 20-40dB




Loss at 1 GHz 26 27 27

Loss at 18 GHz 90 95 100

RFParts suggests that the relay is compatible with LMR195 (which does have a solid centre conductor)... which is quite a deal larger then 2.5D2v (Tohtsu data sheet).

I have bought LMR195 locally, I think from RFshop. You might also see in on RFSupplier.com.

That said, they are not a stunning relay!

Owen

Hi Peter,

I can't tell you about RG188 or RG316 but I think the problem you have will be to find something the right diameter that stays securely in the clamp. If you're talking about short lengths of coax then I'd say they're all much of a muchness and losses will be manageably small. Have you considered .141" semi rigid or quickform? It's almost the right diameter, solid centre conductor and easy to acquire. You'll need to shim the outer to fit snugly into the clamps (use a small piece of .141 outer) but if done correctly will fit very nicely indeed. Suitable connectors are available from minikits.com.au or rfsupplier.com

VK5PJ wrote:Hello,
I have been eyeing off some of the junior TOHTSU relays (Tohtsu CX-140N SPDT N Type Coaxial Relay) for a couple of amplifier projects for the input path only. These junior version have a single type N on the common port and then two spots to push in a cable for N/O and N/C thus reducing the overall cost and the connector count and size taken inside the case.

http://www.tohtsu.com/shouhin.holder/CX-140D.html

My dilemma is that RG-188 is not a cable I have been able to source in VK and I am looking for a main stream equivalent, which seemed to be RG-316 but each time I look at a data sheet for this cable type I get conflicting answers. The TOHTSU relays require the centre of the coax to be solid (common enough I thought) but I now have four different data sheets for RG-316 and they alternate between saying is solid, stranded and in the case of another it just says its silver plated copper over steel.

Do any of the forum members have any real world experience with RG-188 and or RG-316 coax cables? Maybe you can put me out of my misery and give me the real answer

RFshop has RG188 by the roll , must be possible to buy a couple of meters ?

Hi, when I have enquired to each of these online stores, I have been told its only per roll, not sure why this is the case for RG-188, even ebay sellers want to sell rolls only.

RFshop has RG188 by the roll , must be possible to buy a couple of meters ?

Regards,
Peter

RFshop has RG188 by the roll , must be possible to buy a couple of meters ?

Regards,
Peter[/quote]http://www.wellshow.com/spec/cable/Harbour-RG188.pdf specs down the bottom , depending on impedance it might be shave something to firt