I don't think I mentioned the PEP he was running.
In any event, it happens at 1KW or more.
-J
----- Original Message -----
From: Chet Moore
To: jmltinc@aol.com
Sent: Monday, December 29, 2008 7:41 PM
Subject: Re: [TowerTalk] Smoking Rotor Box
keep the power under 1500 W
----- Original Message -----
From: <jmltinc@aol.com>
To: <towertalk@contesting.com>
Sent: Monday, December 29, 2008 5:05 PM
Subject: [TowerTalk] Smoking Rotor Box
> Hello all,
>
> I have a friend (without computer) who has a Yaesu 2800 that has given him
> good service for a couple years. He works all bands from 160 meters
> through 10GHz. All of his amplifiers are QRO homebrew, of the highest
> quality.
>
> He recently constructed 2KW+ amp for 160 meters. All has been well since
> he put it on the air. The other day, he keyed up on 160 SSB and as he
> started to speak, he got a 'poof' from the Yaesu control box and a little
> puff of smoke. He immediately stopped. The rotor still works OK, so he
> opened it up and sees no visible burnt components (but has the tell-tale
> smell).
>
> He scoped each rotor cable wire at the control box and there is plenty of
> RF on each wire on 160 and 75 meters at 100 watts. The amplifiers are
> separate for each band. The (smoking) rotor is for the?10 GHz?dish and the
> only commonality is that all coax (there are dozens) and?rotor cables all
> are routed together to the outside. There is one other Yaesu 2800 and two
> Tailtwisters that are not affected.
>
> Our thought was to choke out the 160 (as no other band has any effect)
> using a toroid on the rotor cable before it enters the box.
>
> Any suggestions as to core and turns?
>
> All suggestions are appreciated.
>
> -John, N9RF
> _______________________________________________
>
>
>
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