For some reason they are often ignored in linear service altho moderately
popular for AM and as modulators. They do well at 813 voltages in GG service
and running 2-4 would make some economical power.
I have an old FAA tuned line VHF amp using them that I converted to 2M
decades ago as an FM amp in contests, cant seem to even put a dent into
their emission. The almost free NIB spares are just gathering dust.
Carl
KM1H
----- Original Message -----
From: "James R Carr" <n7fcf@hctc.com>
To: "Carl" <km1h@jeremy.mv.com>; "Roger (K8RI)" <sub1@rogerhalstead.com>;
<amps@contesting.com>
Sent: Saturday, January 08, 2011 10:41 PM
Subject: Re: [Amps] Fuses
> Are 4-125A's used much anymore? I've accumulated several and a couple of
> sockets. Two appear to be brand new one a JAN, both Eimac and one that
> appears used.
> Jim
> N7FCF
> ----- Original Message -----
> From: "Carl" <km1h@jeremy.mv.com>
> To: "James R Carr" <n7fcf@hctc.com>; "Roger (K8RI)"
> <sub1@rogerhalstead.com>; <amps@contesting.com>
> Sent: Saturday, January 08, 2011 7:00 PM
> Subject: Re: [Amps] Fuses
>
>
>> Never mind the blessings, just send money or your first born.
>>
>>
>> ----- Original Message -----
>> From: "James R Carr" <n7fcf@hctc.com>
>> To: "Carl" <km1h@jeremy.mv.com>; "Roger (K8RI)" <sub1@rogerhalstead.com>;
>> <amps@contesting.com>
>> Sent: Saturday, January 08, 2011 9:32 PM
>> Subject: Re: [Amps] Fuses
>>
>>
>>> Oh bless you your worthiness
>>> ----- Original Message -----
>>> From: "Carl" <km1h@jeremy.mv.com>
>>> To: "James R Carr" <n7fcf@hctc.com>; "Roger (K8RI)"
>>> <sub1@rogerhalstead.com>; <amps@contesting.com>
>>> Sent: Saturday, January 08, 2011 5:46 PM
>>> Subject: Re: [Amps] Fuses
>>>
>>>
>>>>I like it when the commoners react fast.
>>>>
>>>> You may carry on.
>>>>
>>>>
>>>> ----- Original Message -----
>>>> From: "James R Carr" <n7fcf@hctc.com>
>>>> To: "Carl" <km1h@jeremy.mv.com>; "Roger (K8RI)"
>>>> <sub1@rogerhalstead.com>; <amps@contesting.com>
>>>> Sent: Saturday, January 08, 2011 8:09 PM
>>>> Subject: Re: [Amps] Fuses
>>>>
>>>>
>>>>> Excuse us your royal highness
>>>>> ----- Original Message -----
>>>>> From: "Carl" <km1h@jeremy.mv.com>
>>>>> To: "James R Carr" <n7fcf@hctc.com>; "Roger (K8RI)"
>>>>> <sub1@rogerhalstead.com>; <amps@contesting.com>
>>>>> Sent: Saturday, January 08, 2011 4:36 PM
>>>>> Subject: Re: [Amps] Fuses
>>>>>
>>>>>
>>>>>> Can you two get back to earth and keep it somewhat relative to ham
>>>>>> amps in the under 20KW range (-;
>>>>>>
>>>>>> Carl
>>>>>> KM1H
>>>>>>
>>>>>>
>>>>>> ----- Original Message -----
>>>>>> From: "James R Carr" <n7fcf@hctc.com>
>>>>>> To: "Roger (K8RI)" <sub1@rogerhalstead.com>; <amps@contesting.com>
>>>>>> Sent: Saturday, January 08, 2011 7:21 PM
>>>>>> Subject: Re: [Amps] Fuses
>>>>>>
>>>>>>
>>>>>>> Down in prosser, WA about 30 years ago they had a problem with a
>>>>>>> pottato
>>>>>>> processing plant and a mechanic came running into the panel room and
>>>>>>> before
>>>>>>> anyone could stop him threw the main 480v 3 phase breaker. The plant
>>>>>>> was
>>>>>>> under full load with motors up the cazoo. When the back emf hit it
>>>>>>> blew the
>>>>>>> breaker out of the panel. The guy was lucky he wasn't hurt.
>>>>>>> I retired in 2000 and there is a whole raft of devices that have
>>>>>>> come on
>>>>>>> line since.
>>>>>>> Jim
>>>>>>> N7FCF
>>>>>>> ----- Original Message -----
>>>>>>> From: "Roger (K8RI)" <sub1@rogerhalstead.com>
>>>>>>> To: <amps@contesting.com>
>>>>>>> Sent: Saturday, January 08, 2011 2:38 PM
>>>>>>> Subject: Re: [Amps] Fuses
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On 1/8/2011 5:22 PM, James R Carr wrote:
>>>>>>>>> Agreed, The first instant in time you have the full output of
>>>>>>>>> Bonnyville
>>>>>>>>> Dam
>>>>>>>>> on the fault. But then the impedance of the system kicks in and
>>>>>>>>> limits
>>>>>>>>> it.
>>>>>>>>> But still depending on the size of the utility transformer, it's
>>>>>>>>> eficiency,
>>>>>>>>> the length and size of the service conductors, you can still have
>>>>>>>>> several
>>>>>>>>> thousand amps at the main panel and down the line. About 20 25
>>>>>>>>> years ago
>>>>>>>>> they had to increase the fault clearing ability all the breakers
>>>>>>>>> in the
>>>>>>>>> panels from 5000 amps to 20000 amps due to the increased use of
>>>>>>>>> low loss
>>>>>>>> Our mains weren't quite that large, but they were big...It's been
>>>>>>>> too
>>>>>>>> long for me to remember the actual size.
>>>>>>>> They used magnetic quenching in arc chutes. They could open under
>>>>>>>> full
>>>>>>>> load without self destruction, BUT with big transformers down
>>>>>>>> stream
>>>>>>>> (Inductive loads) the "kick back" was so bad that reverse EMF would
>>>>>>>> take
>>>>>>>> out almost any thing attached to the line. So, if you blew one of
>>>>>>>> the
>>>>>>>> mains you knew it was going to be an expensive day.
>>>>>>>>
>>>>>>>> 73
>>>>>>>>
>>>>>>>> Roger (K8RI)
>>>>>>>>> transformers by the utilities. basically the breaker can clear it
>>>>>>>>> without
>>>>>>>>> exploding. It probably will be terminally damaged though. I have
>>>>>>>>> seen
>>>>>>>>> buss
>>>>>>>>> bars twisted into pretsels by a dead short and a breaker that
>>>>>>>>> didn't
>>>>>>>>> clear
>>>>>>>>> quick enough.
>>>>>>>>> Jim
>>>>>>>>> N7FCF
>>>>>>>>> ----- Original Message -----
>>>>>>>>> From: "Jim Thomson"<jim.thom@telus.net>
>>>>>>>>> To:<amps@contesting.com>
>>>>>>>>> Sent: Saturday, January 08, 2011 2:18 AM
>>>>>>>>> Subject: [Amps] Fuses
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> Date: Sat, 8 Jan 2011 08:34:30 +0000
>>>>>>>>>> From: Ian White GM3SEK<gm3sek@ifwtech.co.uk>
>>>>>>>>>> Subject: Re: [Amps] Fuses
>>>>>>>>>>
>>>>>>>>>> James R Carr wrote:
>>>>>>>>>>> Where pray tell do you get a hydraulic breaker? I have installed
>>>>>>>>>>> several thousand over the years but have yet to see one filled
>>>>>>>>>>> with
>>>>>>>>>>> oil. As for current limiting devices, the fastest breaker will
>>>>>>>>>>> hold in
>>>>>>>>>>> for three to seven full cycles. To be current limiting, a fuse
>>>>>>>>>>> has to
>>>>>>>>>>> clear in less
>>>>>>>>>>> than 1/2 cycle.
>>>>>>>>>> A fuse provides NO current limiting until it blows; and a breaker
>>>>>>>>>> provides NO current limiting until it breaks.
>>>>>>>>>>
>>>>>>>>>> A lot of damage can be done in those first few milliseconds,
>>>>>>>>>> which is
>>>>>>>>>> why the fuse/breaker is only PART of the solution.
>>>>>>>>>>
>>>>>>>>>> We always need a surge limiting resistor in the B+ as well, to
>>>>>>>>>> provide
>>>>>>>>>> instantaneous current limiting until the fuse/breaker takes over
>>>>>>>>>> and
>>>>>>>>>> finally breaks the circuit.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>>
>>>>>>>>>> 73 from Ian GM3SEK
>>>>>>>>>> http://www.ifwtech.co.uk/g3sek
>>>>>>>>>>
>>>>>>>>>> ## Agreed. The purpose of the mag-hydraulic breaker is [A]
>>>>>>>>>> handy dandy
>>>>>>>>>> way of opening off the 240 v line, without having to kill the
>>>>>>>>>> dedicated
>>>>>>>>>> breaker in the
>>>>>>>>>> main 200A panel. [B] eliminate any follow on current.
>>>>>>>>>>
>>>>>>>>>> ## On my latest 7700 vdc supply, I use a Buss HVU series, sand
>>>>>>>>>> filled
>>>>>>>>>> HV fuse..rated at 3A..in series
>>>>>>>>>> with the B+ lead. The HV fuse gets inserted just prior to the
>>>>>>>>>> kw
>>>>>>>>>> rated
>>>>>>>>>> glitch R, which consists of 4 x
>>>>>>>>>> parallel globar type AS energy absorbing type resistor's, 1.5"
>>>>>>>>>> diam x
>>>>>>>>>> 18' long. [ 4 x 200 ohm in parallel= 50 ohms]
>>>>>>>>>> 7700/50 ohms = 154A. max fault current. Now 154 A of fault
>>>>>>>>>> current,
>>>>>>>>>> flowing through a 3 A rated
>>>>>>>>>> fuse, will open VERY fast. [ the fuse is running at 5100% of
>>>>>>>>>> it's
>>>>>>>>>> rating]. I use a 50 ohm glitch R on the
>>>>>>>>>> smaller supplies as well... with the provisio that a smaller
>>>>>>>>>> rated HV
>>>>>>>>>> fuse
>>>>>>>>>> is used..like 1A, etc.
>>>>>>>>>>
>>>>>>>>>> ## I also use a 2nd Buss HV fuse, in the sec of the plate xfmr,
>>>>>>>>>> [one
>>>>>>>>>> leg
>>>>>>>>>> only], between sec and input to
>>>>>>>>>> FWB. In normal operation, with any B+ to chassis fault, the B+
>>>>>>>>>> HV fuse
>>>>>>>>>> alway's blows open 1st..so the
>>>>>>>>>> breaker used in the 240 v line is sorta a moot point. That B+
>>>>>>>>>> fuse
>>>>>>>>>> concept has been tested 34 x times
>>>>>>>>>> now, and nothing ever happens..except a blown HV fuse. Once,
>>>>>>>>>> some of
>>>>>>>>>> the
>>>>>>>>>> blown HV fuses were
>>>>>>>>>> 'refurbished' with a single strand, soldered on the outside..and
>>>>>>>>>> wrapped
>>>>>>>>>> with 88 tape. In one case, the
>>>>>>>>>> wire ga of the single strand refurbished job was too big.. and
>>>>>>>>>> the end
>>>>>>>>>> result was the parallel pair of 100
>>>>>>>>>> ohm, 225 W- WW's were literally incinerated, burnt to a crisp.
>>>>>>>>>> That
>>>>>>>>>> was
>>>>>>>>>> with a 165 uf filter cap..and a 253 lb
>>>>>>>>>> dahl hypersil xfmr. That particular glitch R was replaced with 4
>>>>>>>>>> parallel 200 ohm, 225 W, wirewounds
>>>>>>>>>> [ $12.00 each, from mouser],and the correct size HV fuse. Zero
>>>>>>>>>> problems
>>>>>>>>>> since then, and you can literally
>>>>>>>>>> cro-bar it all day long. I would not trust any of these glitch
>>>>>>>>>> R's,
>>>>>>>>>> even
>>>>>>>>>> big ones..without a prior series HV fuse,
>>>>>>>>>> not with big uf caps, huge amount's of joules involved, and then
>>>>>>>>>> trying
>>>>>>>>>> to
>>>>>>>>>> rely on a breaker [ or even the
>>>>>>>>>> 2nd HV AC fuse].
>>>>>>>>>>
>>>>>>>>>> ## In one instance, one of the hv lytics [ 3900 uf @ 450 vdc]
>>>>>>>>>> towards
>>>>>>>>>> the hot end of the string, arced through a
>>>>>>>>>> crack in the plywood, and launched itself. Since the fault was
>>>>>>>>>> before
>>>>>>>>>> the B+ fuse.... the 2nd HV fuse blew.
>>>>>>>>>> [ the one located between sec of xfmr and FWB]. The 96 x 6A10's
>>>>>>>>>> in
>>>>>>>>>> the
>>>>>>>>>> FWB were not damaged. In 2 x instances the
>>>>>>>>>> 240 vac breaker popped open. Once when a screw removed from a 6"
>>>>>>>>>> fan..and
>>>>>>>>>> the AL fan swung down like a pendulum
>>>>>>>>>> and hit one side of the 240 vac buss. [ and blew a chunk out of
>>>>>>>>>> the fan
>>>>>>>>>> casing]. The 2nd time was a B+ fault.
>>>>>>>>>>
>>>>>>>>>> ## I use a simple 50 ohm-50W WW on my L4B's..with the stock
>>>>>>>>>> drake HV
>>>>>>>>>> B+ fuse. [ consist of a .82 ohm, 1 watt carbon R ].
>>>>>>>>>> The stock .82 Ohm R always blows cleanly in 1/2. I have only
>>>>>>>>>> had 2
>>>>>>>>>> x
>>>>>>>>>> ever blow open since 1977.
>>>>>>>>>>
>>>>>>>>>> later... Jim VE7RF
>>>>>>>>>> _______________________________________________
>>>>>>>>>> Amps mailing list
>>>>>>>>>> Amps@contesting.com
>>>>>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>>>> _______________________________________________
>>>>>>>>> Amps mailing list
>>>>>>>>> Amps@contesting.com
>>>>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> Amps mailing list
>>>>>>>> Amps@contesting.com
>>>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Amps mailing list
>>>>>>> Amps@contesting.com
>>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>
>>>>>
>>>>
>>>
>>
>
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