Little mor eupdate..
i was wrong about hte transfomer taps the newer amp (the one I just got) is
wired for the factory 120 volts default and I get 1600 volts the amp that I get
more power out of is wired for 100 volts at the transformer and gives me 1850
to 1900 volts. Could this be the difference in output or the blackened tube?? I
still wonder what trouble i get into by swapping out the 811a between the two.
actuall I believe the older amp wired for 100 volts abd giving me 1900 volts
might actually be the one that should be changed to prevent early death to the
tubes.. manual says nominal 1700 volts///
anyway you guys are the experts most concerned abott he startup spark, large
power surge and smell but might that be due to sitting 2 yrs..It rusn fine now
and seems to have power out but bot as much as the other older amp
any and all ideas are appreciated.. thanks
Dan
----------------
Well I received the amp looks really clean inside and out.. checked it all out
very close.. one of the tbes appears to be blackened in the lower glass at one
spot above the base. Does that mean anythign important at this stage.
second question.. I decided to do the quick switch on and off to see what
happens.. man that was exciting.. flip switch on and amp lights came on kinda
loud spark and smell of sometign burit. also it took such a chunk of power it
rebooted my computers on the sam eline.. swichted it all off pulled plug took
case off again.. did not see anythign that might indicate anythign burnt etc..
still looks clean..
sooo being a brut for punishment I put the case back on and hit the switch
again. this time all seemed ok.. at least for about 10 secs then a small pop
and i could see a little arc at the vents near the 4 tubes. switched it off..
seemed ok so switched it back on (I know I know).. anyway this time all was
fine.. had on abt 1 hr no problems voltage reads a little lower then my other
811H on same line this one reads 1600 and the other reads 1800.. seems tapped
same way..
anyway decide to try a small load into it works fine at least it appears to..
now more questions.. It appears on the same exciter and antenna I can not get
quite the output that the other 811H gets.. where on the other I get 600 + on
20 meter with little drive seems this only want to do about 450 or so.. can
that be an indication that the blackened tube is bad??
one more questions since I have the other 811H what problems would I be causing
if I swapped the 4 tubes form the other amp to this one? I thought that may
tell me if a new set of tubes woudl help twiththe output of this amp.
Also.. any ideas about the start up problems sta6ed above?? it is runngin right
now stil showing only about 1600 volts but I have tested it on 3 bands seems
just fine just a little lacking in power output..
thanks for any suggestions.. I woud like ot hear opinions about swapping the 4
811A form the know good amp to ths one for a est..
thanks
*********** REPLY SEPARATOR ***********
On 12/07/2004 at 10:06 PM Pat Poirier wrote:
>Hi Dan,
>
>If your amplifier that has been stored is only two years old, it shouldn't
>be a big deal to turn it on and just let it idle for several hours. If the
>amplifier was manufactured more than 5 years ago, I would use a variable
>AC
>voltage transformer to bring the power up from low voltage to full voltage
>over a short time.
>
>I would first start out by inspecting the power supply and making sure
>that
>there is nothing leaking or growing out of the electrolytics. If there is
>nothing and the amplifier isn't that old, I would turn it on and then give
>the tubes several hours just idling with no RF power to make sure that
>they
>are burned in and that they are not gassy. Then you should be all set to
>power it up.
>
>73,
>
>Pat W1KA
>----- Original Message -----
>From: "Dan" <dpipes@earthlink.net>
>To: <Amps@contesting.com>
>Sent: Tuesday, December 07, 2004 9:27 PM
>Subject: Re[2]: [Amps] 811A - Tubes
>
>
>Pat,
>Thanks for the info. now you bring up another question. I have bought
>another 811H thathas been stored for abotu 2 years. stored in a a clean
>dry closet inside plastic bags etc so it is very very clean.
>might be a stupid question but... is there anythign i shold do or maybe
>NOT
>do when I first fire it back up? Can sitting there for two years actually
>hurt the amp? i woudl think that some store stock could get stored that
>long or maybe warehouse stock..
>
>Just curious this list has smoe real experts ,g. and I just do nto want to
>screw up a perfectly good amp by bringing it out of storage and maybe
>doing
>somethign wrong on re-start
>thanks
>Dan
>
>*********** REPLY SEPARATOR ***********
>
>On 12/07/2004 at 8:41 PM Pat Poirier wrote:
>
>>Hi Dan,
>>
>>Don't bother spending the extra money on the Svetlana 811's. I had four of
>>the white ceramic base Svetlana tubes in my AL-811H.
>>
>>I purchased a matched quad from RF Parts of their Taylor Brand 811A's and
>>they were the same output that my Svetlana tubes were.
>>
>>My AL-811H is used as a back up to my backup amplifiers and it is very
>>seldom ever used except to turn it on for an hour or two idling to keep
>>the
>>electrolytics formed every six months.
>>
>>For $77.20 from RF Parts I don't think you can go wrong. Don't bother
>>looking at 572B's you will not see any more power and they are 2 1/2 times
>>the price.
>>
>>Good Luck,
>>73,
>>Pat W1KA
>>
>>----- Original Message -----
>>From: "Dan" <dpipes@earthlink.net>
>>To: <amps@contesting.com>
>>Sent: Tuesday, December 07, 2004 8:06 PM
>>Subject: [Amps] 811A - Tubes
>>
>>
>>I need 4 811 A tubes for my Ameritron 811H. I have read some say th
>>Russain
>>tubes are best some the centron etc.. What are the opinions and where is
>>the
>>best place to buy a set of 4...
>>Thanks
>>Dan
>>
>>
>>
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>
>
>
>
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