[Milsurplus] RCA phono connector impedance

[Jim Whartenby]

The RCA phono connector doesn't seem to be a bad choice.  In fact, it is looks pretty darn good considering the cramped space of the rear apron of the KWM-2.  See:https://wv0h.blogspot.com/2014/11/rca-phono-connector-characteristic.html
It might be worth noting that only one of the Collins supplied RCA phono cables for the KWM-2 was meant to be used as RF coax.  The rest are just for interconnecting the KWM-2 to other equipment with no regard to impedance.Regards,Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.  Murphy 

    On Wednesday, November 29, 2023 at 10:47:17 AM CST, mstangelo at comcast.net <mstangelo at comcast.net> wrote:  
 
 The RCA was a bad choice but as Ken mentions Collins had a cult following. I would replace the RCA connectors with BNC connectors.

Mike N2MS

> On 11/29/2023 11:28 AM EST Ken <kgordon2006 at frontier.com> wrote:
> 
> 
> Yes.
> 
> The ceramic-insulated RCA connector is far more likely to not introduce an impedance "bump" at the connection, unlike the SO-239 which does: but since the PL-259 is almost ubiquitous at the ends of RF cables, I suspect THAT is the main reason so many of us change our Heathkits to the SO-239.
> 
> In the case of Collins owners, the initial cost of their rigs coupled with their overweening "respect" for Art's designs preclude them from "desecratimg" those rigs in the interests of convenience.
> 
> In addition, of course, the PL-259-to-RCA converter is so un-reliable that it must be treated carefully to ensure constant contact, especially when the use of RG-8 sized cable is involved.
> 
> Ken W7EKB
> 
> 
> Sent via the Samsung Galaxy S21 5G, an AT&T 5G smartphone
> 
> 
> -------- Original message --------
> From: Mike Morrow <kk5f at earthlink.net>
> Date: 11/29/23 06:11 (GMT-08:00)
> To: milsurplus at mailman.qth.net
> Subject: Re: [Milsurplus] Nomenclature Tags
> 
> The US military purchased the KWM-2A as the RT-718/FRC-93.
> 
> The KWM-2A was introduced in 1961. Just by itself...no power supply, microphone, speaker, or any other accessories...it sold for $1,250. That is equivalent to $13,000 today.
> 
> The Collins S-Line used RCA phono connectors everywhere except the RF output of the 30L-1 and 30S-1 amplifiers. For almost 60 years it has amused me to see ham "engineneers" very frequently replace the same quality ceramic insert phono sockets on Heathkits with SO-239 sockets in false belief that the SO-239 is a superior RF connector. Yet, one almost never heard of a Collins S-Line owner doing likewise. :-)
> 
> Mike / KK5F
> 
> -----Original Message-----
> From: Bruce MacMillan <wirelessset at hotmail.com>
> Sent: Nov 29, 2023 12:05 AM
> 
> A former co-worker used to work for Collins in Australia. He said on more than one occasion a KWM2 would have S/N's removed before it was "gifted" to a friendly party.
> 
> Bruce
> M0SOE
> 
> 
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
______________________________________________________________
Milsurplus mailing list
Home: http://mailman.qth.net/mailman/listinfo/milsurplus
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Milsurplus at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20231129/669f4af9/attachment.html>