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Re: Attenuators

 

Bruce, I did not mean to be rude.? I usually use the term "newbie" but worded it as I did to avoid rudeness.? I've just viewed so many.,....many YouToob presentations which are just blatantly wrong and? against all basic electronics and physics principles.? And the uninitiated believe them and snake oil becomes conventional knowledge.? I generally no longer view any Youtoob unless it's done by professionals.? At times I become so frustrated with the snake oil and witchcraft that I err on the knee jerk side of a reaction.? Yes, it's rude, but I have no idea of the background of emailers.? Sorry I might have offended anyone, but please understand my background as well.? I generally assume the poster has a very basic understanding of electronics and a bit of physics.

These groups exist to help others who have legitimate and good questions.?? But I can't go back to the rank basics of electronic theory.? After all, passing the ham license is supposed to instill that basic understanding of electronics, antennas, and feedlines.? I won't take that comment further as it's one of my hot buttons with the "memorize and forget" philosophy.??

I had a real honest Ohm's Law question on my Novice exam in 1959 way back when we had to show calculations.? And a real honest Smith Chart problem on my Advanced and Extra exams - in front of FCC - in roughly 1974.

BTW:? Of some 30++ potential engineers I interviewed while working at HP in Northern Colorado, none, yes, NONE, of them could put the DC case of Ohm's Law on the white board!!!? I had one, yes, ONE, technician candidate who could put Ohm's Law on the white board, but struggled a bit to use it.? He eventually made it work.? Needless to write, we hired?him with no further questions asked.

Dave - W?LEV


On Thu, Jun 20, 2024 at 3:55?PM Bruce Akhurst via <bruce=[email protected]> wrote:

Dave

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I'm not a newbie by a long way and as I stated earlier was first using professional spectrum analysers in VHF UHF comms design, manufacture and field repairs in the 1970's.? Doesn't mean I know everything but? . .??

I have not taken any SMA attenuators to bits and based on previously taking BNC style ones to bits I wasn't sure I could evaluate the power handling of the input and output resistors on sight even if I did.? ?If you have then thankyou for sharing your insights and can you therefore tell me why many /most sellers of these cheap 2W SMA (and BNC) attenuators go to great lengths to specify the input and outputs (consistently as Male = input.)

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As I said previously I've much experience with expensive Bird HP etc attenuators and terminators and their attenuators will indeed (mostly) be described and ordered (at a price) as bi directional (with unidirectional available on some items)? and this is what we did for the reasons I said already.? ? ?

Personally I'm very happy if the 10x cheaper ones from China exist and can be 10x cheaper by being uni-directional above a watt or so or any other non problematic reason.? No doubt this 'flaw' is a relief to Bird /HP as well?

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No, I am not a You tube Fan - I think your comment is verging on rude but maybe its just mis-aimed - I Learnt and used my Electronic, RF and Comms engineering skills and qualifications the old way; at Work? and college.? (And How do we know / Is this still true/ are we sure? was never a question you'd get your ear clipped for..)

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Anyway , clearly I've offended you so I'll leave this thread in your capable hands

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Dave - W?LEV
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