replacement RG174 50 ohm coax - any difference ?

[vjekobalas]

Maybe someone with good  RF knowledge could clarify whether the replacement
cables I found would be compatible as I couldn't find the original cable in short lengths.
The problem is that there is variation in conductor material (copper/copper clad steel)
and resistance of shield. If the replacements are questionable, I will just put the original
ones back and keep searching for that type for a later replacement.

I would like to replace two 3m 50 ohm RG174 coax cables soldered to ultrasound transducers
in a beauty parlor ultrasound machine head and BNC connected to the machine
(15W collimated beam, 1MHz/20-60KHz modulated frequency) as I am replacing
other cables in the bundle.The cables undergo certain heating as well as movement
at the ultrasound head end and have hardened there.

Original RG174 cable is the Prospecta I043. According to the spec, the inner conductor is
copper stranded wire (a strong magnet confirms this).

The other cables are all copper clad steel except, I am not certain about the cable from mauritz
the sales person said copper (the spec says full copper and then "Staku" -maybe a native German
speaker can confirm,

[2N3055]

StaKu is short for Stahl-Kupfer (Stahlkern mit Kupfermantel).
Meaning steel core with copper surface. Those cables can have good performance but I guess full copper cable made from strands will be softer and withstand bending better. And I would think you need that.

These would be exactly what you need , take 2 and snip off SMA connector.
https://hr.mouser.com/ProductDetail/Amphenol-Cables-on-Demand/CO-174SMAZBNC-010?qs=BA62vJVifGqS1zIRp2dfQA%3D%3D
Unfortunately not in stock...

But if you get good cable and connectors these could be crimped no problem. Frequencies are very low.

[vjekobalas]

I found this one in stock:
https://hr.mouser.com/ProductDetail/Amphenol-RF/095-850-249M300?qs=W%2FMpXkg%252bdQ4okyQCxuk6DQ==&utm_source=eciaauthorized&utm_medium=aggregator&utm_campaign=095-850-249M300&utm_term=095-850-249M300&utm_content=Amphenol
but no info on cable.

I wouldn't have anything against crimping but I don't have any crimping tools and
as far as I understand anything good is costly and I don't see myself making
any use of the tool afterwards. Other than that, I didn't find a similar cable
(all are copper clad steel) and the original needs to be purchased in 100m length.
I also need to wrap this up with the cables this week as the machine is needed 

[vjekobalas]

I found this one with 2 BNC connectors / cable description is the same:
https://www.digikey.si/en/products/detail/amphenol-cables-on-demand/CO-174BNCX200-025/13877687?s=N4IgTCBcDaIMIHkC0BGA7AFgEIDk4A0wAGIpIsAVhAF0BfIA
The only question is - is there any possibility that a difference in coax requires
some sort of adjustment in the machine (I have no service manual, no voltage/signal levels
to compare to - or am I overthinking this -it's not an ultrasound imaging device
the machine just sends out the signal/ couldn't be that much difference
in effect from the cables right ?

[2N3055]

I found this one with 2 BNC connectors / cable description is the same:
https://www.digikey.si/en/products/detail/amphenol-cables-on-demand/CO-174BNCX200-025/13877687?s=N4IgTCBcDaIMIHkC0BGA7AFgEIDk4A0wAGIpIsAVhAF0BfIA
The only question is - is there any possibility that a difference in coax requires
some sort of adjustment in the machine (I have no service manual, no voltage/signal levels
to compare to - or am I overthinking this -it's not an ultrasound imaging device
the machine just sends out the signal/ couldn't be that much difference
in effect from the cables right ?

No need to adjust anything, cable specs (electrically) will be just fine. Problem is mechanically, if that is a moving probe (and it is) then cable has to be soft and pliable so it doesn't break inside from movements.


If you're in a hurry, any cable will do, it's just it might not last long...
 

[vjekobalas]

Your input is much appreciated ! I will then purchase the cable I found.
The cables are in a flexible steel wire (spring shape) supported conduit
and from the present group of cables, the multicore 4x2x0,25 signalling
cable is the only one that has been damaged - the coax and one 2x0,34
cable are OK but hardened near the ultrasound head (I am assuming from heat and movement)
so I hope all will be well - now to order the cable and to try to put it together
again