[Amps] Amps Digest, Vol 98, Issue 26

[Dave Weiss]

*AL-82 Blowing fuses:*

*Gary,* it seems like it's time to open the amp and look for poor solder
joints, loose wires, unsolder ed connections.  Basically a check for final
assembly mistakes.   Use caution when entering the amp.  Unplug, let drain
and view the HV meter before going inside.

Post findings for others.

Dave K3FT

On Tue, Feb 22, 2011 at 3:00 PM, <amps-request at contesting.com> wrote:

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> Today's Topics:
>
>   1. Source for TL-922A Fuses (George Hall)
>   2. Alpha 77 start up (Jan Ditzian)
>   3. EB-104 amp and assorted parts (Mike Short)
>   4. Al-82 Blowing fuses? (Gary Smith)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 21 Feb 2011 17:04:30 -0500
> From: "George Hall" <N2CG at VERIZON.NET>
> Subject: [Amps] Source for TL-922A Fuses
> To: <amps at contesting.com>
> Message-ID: <000801cbd213$50cdfe80$f269fb80$@NET>
> Content-Type: text/plain;       charset="US-ASCII"
>
> Greetings Amps Gentlemen,
>
>
>
> I just completed some mods (step-start, glitch resistor, glitch fuse) on my
> friends Kenwood TL922A amplifier.  He recently blew one of the 15A line
> voltage fuses and temporarily installed a 30A fuse so I would be able to
> test the mods I installed when I powered on the amp.
>
>
>
> Before I place this amp on the air, I would like to install the proper 15A
> @
> 250V fast blow glass fuse.  I looked in Mouser Electronics catalog but did
> not find this fuse which measures ~0.4" diameter x 1.5" long  or ~10.3mm
> diameter x 38mm long.
>
>
>
> Kindly advise a source where these fuses are available.
>
>
>
> Thanks,
>
>
>
> 73, George  N2CG
>
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 21 Feb 2011 17:31:07 -0500
> From: Jan Ditzian <ditzian at windstream.net>
> Subject: [Amps] Alpha 77 start up
> To: Paul Christensen <w9ac at arrl.net>
> Cc: Amps at contesting.com
> Message-ID: <4D62E7AB.20008 at windstream.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Paul,
>
> I did some investigating and some testing.  First, two of the three
> bulbs were bad.  I cannot get these locally, so I have ordered both
> meter and switch bulbs on the internet and they will arrive in a few
> weeks.  Meanwhile, I put the good bulb into the standby switch, and it
> turns out that the delay appears to be working properly--the lamp lit
> after a few minutes warm-up.
>
> Now comes the bad part.  I connected a dummy load to the amp RF output,
> and I connected the exciter rf to the amplifier (this is the first time
> that I have done this), and I connected the exciter relay switching to
> the relay connection on the back of the amp.  At this point, I saw that
> the swr on the exciter swr bridge was high.  I double-checked all
> connections, and used the same cable to connect the exciter directly to
> the dummy load, where the swr was 1:1.  I then thought that perhaps
> there was a stick relay in the amp, so I went ahead and connected
> everything back as one would expect to use th amp.  I pressed the CW/Low
> switch on the amp, and I turned the exciter power to zero and turned on
> the exciter, and then brought up the power a little.  I saw some grid
> drive at the amp but no plate current.  I unkeyed, turned up the exciter
> a little more, and the grid current went up a little more, still near
> the bottom of the meter.  I repeated this with a little more drive (the
> exciter still showing a high swr, and this time no grid current showed.
> I turned the amp off, and again checked to see the swr at the exciter;
> it was still high,despite the fact that it should have been looking
> directly at the dummy load through the amp switching.  Then I wrote this
> e-mail.
>
> Jan, KX2A
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 22 Feb 2011 06:23:57 -0600
> From: "Mike Short" <mike.short at mchsi.com>
> Subject: [Amps] EB-104 amp and assorted parts
> To: <amps at contesting.com>
> Message-ID: <013301cbd28b$60df86e0$229e94a0$@short at mchsi.com>
> Content-Type: text/plain;       charset="us-ascii"
>
> EB-104 from Communications concepts. Complete kit including heatsink,
> copper
> spreader, etc. LPF board from ALS-600 amp,front panel and meters from
> ALS-600. two computer power supplies that will power this, transformer and
> other parts for linear power supply. Other pics available on request $600
> OBO shipped or trade?. mike.short at mchsi.com
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 22 Feb 2011 07:42:19 -0800
> From: "Gary Smith" <wa6fgi at sbcglobal.net>
> Subject: [Amps] Al-82 Blowing fuses?
> To: <amps at contesting.com>
> Message-ID: <17FBB302C41C4FBAAB3110728683261F at gary1>
> Content-Type: text/plain;       charset="iso-8859-1"
>
> Hello to the list.
>
> My AL- 82 (4 months old) blows the two fuses on the rear panel for what
> seems to be no reason at all.  Switch on the power, fan rolls up to speed,
> all seems well. Either when tuning or at a already tuned position, one or
> both of the fuses lets go.
>
> Replace the fuses, switch the amp back on again and all is well for no
> particular length of time. It might go a week or a month,it make take out
> two fuses in a few moments. A
>
>  Thought I'd poll the members of this list for ideas before calling
> Ameritron. Fwiw, it is on 240V, line voltage is very stable here in
> Sacramento county.
>
> Anyone else having this quirky issue?
>
> Gary...wa6fgi
>
> ------------------------------
>
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> End of Amps Digest, Vol 98, Issue 26
> ************************************
>



-- 
Dave  K3FT