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SB220

kopcicle

Sr. Member
Feb 17, 2016
2,087
3,378
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I was given a wreck of an SB220. I've found most of the necessary parts. Looking for the internal, top, RF/HV shield.

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Yup, gonna be some body work.
 

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In the case of two 4-400C Electron Tubes, running Class AB, the best plate load
resistance (R L ) which will transfer the maximum amount of available power to the antenna is;
R L = Ep / K x Ip = Ep / 1.5 x Ip = 3,000 VDC / 1.5 x 666 ma = 3003 Ohms
Note:
1.Load Resistance (RL) will be half that of a single tube.
2.Power output (Po) will be double that of a single tube.
3.Power input ('Pi'), Cathode to Plate will be double that of a single tube.
4.Plate idling (quiescent) current will be double that of a single tube. (I.e. 35mA to
70mA)
 

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Fed Ex delivery men in some areas of the US are self employed. They do NOT work directly for Fed Ex as employees, they are sub contractors. If a delivery is damaged in shipping and Fed Ex gets a claim on it and it is discovered that the delivery guy was at fault, Fed Ex deducts the amount of the claim from their pay. It is NOT like this with UPS so therefore you will generally get much better handling of packages with Fed Ex. Been using Fed Ex for years now with no claims against them. hundreds of packages delivered unharmed whereas with UPS it was almost every time.
 
Around here, most of the FedEx drivers are subcontractors. And they are the absolute worst. They leave packages at the wrong address, damage packages, even falsely claim incorrect address and send my package back. And, they drive through this 25 mph residential area as if they were on the highway.
UPS is so much better, there is no comparison. I can't even remember the last time I had any problem with UPS.
 
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Fed Ex delivery men in some areas of the US are self employed. They do NOT work directly for Fed Ex as employees, they are sub contractors. If a delivery is damaged in shipping and Fed Ex gets a claim on it and it is discovered that the delivery guy was at fault, Fed Ex deducts the amount of the claim from their pay. It is NOT like this with UPS so therefore you will generally get much better handling of packages with Fed Ex. Been using Fed Ex for years now with no claims against them. hundreds of packages delivered unharmed whereas with UPS it was almost every time.

Every package I have ever had delivered that the packaging was in bad condition has been with UPS or USPS & one UPS package even had tire tracks across the package but because it was a solid aluminum mount it was not damaged just the package.FedEx has always been spot on with Zero damage to the packaging or the items that were received.USPS has left items out in the rain,received with the package opened & items missing as well.We don't have a local FedEx or UPS Store being in a rural community so I ship everything by USPS from here but I request FedEx when having any item shipped to me if it's possible to do so.I HATE shipping anything & will avoid it if at all possible.

SIX-SHOOTER
 
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Around here, most of the FedEx drivers are subcontractors. And they are the absolute worst. They leave packages at the wrong address, damage packages, even falsely claim incorrect address and send my package back. And, they drive through this 25 mph residential area as if they were on the highway.
UPS is so much better, there is no comparison. I can't even remember the last time I had any problem with UPS.
How often do you ship 50-100 lb amplifiers with UPS?
 
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How often do you ship 50-100 lb amplifiers with UPS?
I occasionally ship heavy and/or fragile items. On two separate occasions recently I have received large PV (solar) panels via UPS. In both cases they showed up on time and undamaged.
Based on my personal experiences with FedEx, if when I was shopping for those panels I found them at a price I liked but with FedEx as the only shipping option, I would pass on that seller.
 

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