[R-390] R-390A -relay problems.

[Bob Young]

You nailed it Tim, it was the inrush limiter, when plugged into regular 
house current with no limiter it works fine

Bob KB1OKL



>From: "Tim  Shoppa" <tshoppa at wmata.com>
>To: <r-390 at mailman.qth.net>, "Bob Young" <youngbob53 at msn.com>
>Subject: Re: [R-390] R-390A -relay problems.
>Date: Wed, 26 Sep 2007 15:01:10 -0400
>Bob writes:
> > Recently on start up from off to standby I get a loud buzzing noise for 
>a
> > few seconds then a click and the power goes on which sounds like a bad
> > relay, when I click it to AGC from standby I get another click which 
>sounds
> > like another relay and this one (?) works fine, are there two relays in
> > 390A's? I always assumed there was only the antenna relay. If there are 
>two,
> > which one would close from off to standby as it is going to go kaput 
>very
> > soon. Once the radio has been on for a while it will shut off and on 
>fine
> > from off to standby, it is only from a cold start that i have a problem,
> > thanks,
>
>The antenna relay is run by 25VAC that has been rectified to 120Hz approx
>20V average pulsating DC by the selenium rectifier CR102.
>
>If half of the selenium bridge has failed, you get 60Hz approx 10V average
>pulsating DC to run the antenna relay coil, and you (no surprise) end up 
>with
>a buzzing relay.
>
>The breakin relay is run by 6.3VAC.
>
>But... have you possibly (either internally or externally) installed a
>inrush current limiter? This will cause the buzzing on cold startup
>symptom you're reporting too, and is perfectly normal with an inrush
>limiter.
>
>Tim.
>
>