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New amp fired up for the first time. 3cx3000A7




 
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March 27, 2017, 10:36:09 AM *
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Author Topic: New amp fired up for the first time. 3cx3000A7  (Read 885 times)
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KD6VXI
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« Reply #25 on: March 16, 2017, 11:45:50 PM »

With the proliferation of projects, I'm contemplating the brake, shear, etc for 4 hundred at Harbor Freight.  It's harbor freight, but that sure would make a LOT of strap out of copper sheet!  :-)

I know about cool amp silver rub, used it on a couple tanks before.

My initial reason for braid was multiple.  I wanted flexible, so when things expanded and contracted things wouldn't break or be stressed.  And the original vac cap on CTune was too large, so I was hoping for a bit more inductance.  What I didn't take into account was, all those micro edges between each piece of braid, etc. As you and 'www explained.  Thanks, now I have an understanding of WHY it's bad juju.

The Q is designed at 6......  Another reason CTune had to be so small.  An exciter with predistortion  will be used, with the final pa wrapped into it) so the slight increase in imd wasn't too much of an issue.

When I pull the deck again, I'll take pics, but I used 1/4 inch copper tubing from CLoad to the output relay. It supports the back end of the vac variable.  Punched a 3/4 inch hole and routed top to bottom of chassis.

Got ya on the ceramic post to unload the rear of the vac variable on CTune. I was wondering about a piece of strap bent into a U to somewhat support the rear of the cap? As stated earlier, CLoad is supported front and rear.  CTune only by 3 stand offs on the front.  That seal carries a bit of weight now that you brought it up. 


YES the air filter mesh is intact.  I am thinking of a new home AC air return folded filter in front of it. Other than as a spectator on a bunch of mountain top sites, I've no experience with this type of operation...  The owner has done some repeaters....  I'm leaving the wherewithal of getting cooling  etc. Up to him.  I've increased the blower size.  More air means more cooling, but more dust too.

Wish the service panel was bigger here.  I've got a hundred amp service with a 90 amp feed to the shop.  I'm moving the meter main to the rear of my shop, which will drop my service drop about a hundred feet.  At the same time, I'm upgrading to 200A service so the house will get the 90 amp breaker instead of the shop lol.  Priorities!

--Shane
KD6VXI
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KD6VXI
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« Reply #26 on: March 23, 2017, 10:09:12 PM »

Lesson learned about the braid.

Strap came in today, sheared it down and replaced the braid in the tank.

The piece from tube to CBlock had discolored.. The high impedance node from CBlock to CTune was fine, but from the end of the tank coil to CLoad was also discolored presumably from heat / current.

Still waiting on the new cap for the underside / Tuned input. Hopefully this doesn't change the tank much, I'm happy with the coverage.

--Shane
KD6VXI


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w1vtp
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« Reply #27 on: March 23, 2017, 10:38:04 PM »

My California Kilowatt.  IOW, let's make legal limit AM.

Well, almost done.  Did a test fire today  no fires or smoke except into the dummy load!

Power supply is Pete Dahl (new, not original) 4kv 3A CCS xformer, cap input with A FWB of K2AW diodes.

Has 242 volts on standby, 230 volts full power.    As such, it's 7.5 volts on the filament standby and 7 under fire.

I don't think I need the extra emissions of the half volt....

Pics speak for themselves.  I was able to keep the pep value all the way down to a 250 Watt carrier with my assymetry board, but if you don't have a sync detector  or sdr....

--Shane
KD6VXI

Suggestion: move your light source off to one side so the glare from it won't make the meter unreadable

Al
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KD6VXI
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« Reply #28 on: March 23, 2017, 10:51:53 PM »

Yeah, I need to experiment with the lighting.

I just installed a bunch of led shop lights and now it's so bright taking pics is hard.  I may put switches in so I can not light certain areas.  I already did over my primary operating area.

--Shane
KD6VXI
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KD6VXI
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« Reply #29 on: March 24, 2017, 08:44:34 PM »

I thought he was going with an ANAN 10 for the exciter  and an 8930 as the driver  in close to  or in class A.

Today, this arrived to set up with the amplifier.  As well as the K3S.

I almost prefer the ANAN so as to be able to wrap predistortion around it, but we will see how this combo fairs......

--Shane
KD6VXI


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