[R-390] Soft-Starting and R-390/URR

[Jordan Arndt]

I have CL-90 limiters installed in my 390As. They are connected in series 
between FL-101 and the primary fuse mounted beside FL-101 with long 
insulated leads and as out in the open as possible...The heat from the CL-90 
is partially vented upwards through the PTO cable opening and also spreads 
throughout the cavity where the PTO is mounted. I've never been able to 
measure any PTO instability or drift due to the additional heat.

Yes, it is a rather long soft-start, but it works very well..

73...Jordan VE6ZT

----- Original Message ----- 
From: "Barry Scott" <72volkswagon at gmail.com>
To: "R-390 Mailing List" <r-390 at mailman.qth.net>
Sent: Thursday, September 26, 2024 8:29 PM
Subject: [R-390] Soft-Starting and R-390/URR


>I have a small aluminum box I built long ago that has an IEC male
> connector, a three-prong power outlet, a fuse, and a CL-80 inrush current
> limiter.
>
> I've been leaving the R-390/URR powered through my homebrew metered
> autotransformer that measures both voltage and amperage.  When I have it
> connected that way, at power, the 5A meter is pretty much slammed to the
> right for just a brief moment (expected).
>
> As a test, I incorporated the CL-80 between the autotransformer and the
> radio.  I was somewhat surprised at the difference that makes.  The meter
> now only jumps to around 3A and then settles at the normal current demand.
>
> I've used these before but never where I could do a before/after
> comparison.  It was pretty revealing.  The box gets a little warm after a
> while (30 minutes or so) but not all that bad.  The CL-80 should probably
> have more air around it or the box could have a decent heat-sink but,
> overall, I think it's okay as-is.
>
> Still having a lot of fun with the "new" radio.  It sure sounds better
> after getting the RF, variable IFs, and the IF aligned.
>
> Thanks,
> Barry - N4BUQ
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html