LOL LOOK AT THE SCOPE. Especially when he says it looks good

[rabbiporkchop]

RPC,

Are we going to go down this road again?

Are we going to do quotes from the Bird manual again?

here is a quote from the Bird 4314 manual that RPC so loves to post about:

"When a Model 4314B is used to match a load to a transmitter and a good match is obtained, removing the instrument will not cause any change in the conditions. A well matched 50 ohm load can be placed at the end of a 50 ohm transmission line of any length without altering conditions at the transmitter."

What on earth does this video have to do with connecting different pieces of test equipment together with tuned lengths of coax on a test bench?

Why would Mark use anything but a purely resistive load when doing his testing?

why would the accuracy of whatever measurement is taken using a reactive load in his shop matter at all to the person hooking the transmitter up to their personal antenna?

Is mark recreating the exact conditions of someone's antenna setup in order to tune their amplifier?

Do professional RF labs work this way?
LC

It hardly seems logical to use random length cables when using a purely resistive load, then when using the reactive load, stop what you're doing, and switch cables for the reactive load then toss the random cable for the resistive load. Much simpler to set the bench up so you can switch between loads with the flip of a switch.
Saves time and gets the job done quicker.
If an amp goes into self oscillation at 45 ohms, and you only have a 50 ohm load, the only way you'd know is when your customer blows up his amp and blames you for it. Nice to get it dialed in before sending it to the customer. Postage and transistors are expensive. Best to do it right the first time.

 

[543_Dallas]

It hardly seems logical to use random length cables when using a purely resistive load, then when using the reactive load, stop what you're doing, and switch cables for the reactive load then toss the random cable for the resistive load. Much simpler to set the bench up so you can switch between loads with the flip of a switch.
Saves time and gets the job done quicker.
If an amp goes into self oscillation at 45 ohms, and you only have a 50 ohm load, the only way you'd know is when your customer blows up his amp and blames you for it. Nice to get it dialed in before sending it to the customer. Postage and transistors are expensive. Best to do it right the first time.

If the amp wasn't an unstable pile of junk this wouldn't be an issue. Even with a terrible mismatch it shouldn't be oscillating. Many cb amps do this and cbers have been hiding the issue with magic coax lengths for years.

I suppose it's more profitable to sell these tuned jumpers to people that believe the sales pitch than to actually spend time trying to rework the junk equipment.

 

[rabbiporkchop]

If the amp wasn't an unstable pile of junk this wouldn't be an issue. Even with a terrible mismatch it shouldn't be oscillating. Many cb amps do this and cbers have been hiding the issue with magic coax lengths for years.

I suppose it's more profitable to sell these tuned jumpers to people that believe the sales pitch than to actually spend time trying to rework the junk equipment.

Seems logical to save the customer money by getting the job done as quickly as possible regardless of which method is used, as long as the results make the customer happy and reliable performance is achieved.

 

[Low_Boy]

And the readings can clearly be seen to be different. What's your point? Only one measurement can be correct.

Only problem is I watch videos on you tube and people ball up coax, then stretch it out and even install multiple connectors and the SWR never changes. Why do fine tunes numbers always change?

 

[rabbiporkchop]

Only problem is I watch videos on you tube and people ball up coax, then stretch it out and even install multiple connectors and the SWR never changes. Why do fine tunes numbers always change?

Without seeing these imaginary videos, I can't answer the question.

 

[Dmans]

 

[undertaker]

same shit different day......................

 

[543_Dallas]

Seems logical to save the customer money by getting the job done as quickly as possible regardless of which method is used, as long as the results make the customer happy and reliable performance is achieved.

I have no problem with that if the customer knows it's a bandaid repair and is cool with it. The misleading sales pitch is unethical.

For someone that splits so many hairs and wants everything to be perfect you're quick to approve a half assed repair. Kind of hypocritical isnt it?

 

[rabbiporkchop]

I have no problem with that if the customer knows it's a bandaid repair and is cool with it. The misleading sales pitch is unethical.

For someone that splits so many hairs and wants everything to be perfect you're quick to approve a half assed repair. Kind of hypocritical isnt it?

If the desired result is identical, and one procedure costs twice as much, I don't see the problem with saving the customer money.

 

[543_Dallas]

If the desired result is identical, and one procedure costs twice as much, I don't see the problem with saving the customer money.

You don't even know what the "other procedure" is because were talking hypothetically about an amplifier that has some kind of problem. Might be cheaper to fix the amp than buy some overpriced magic jumpers. Youre not thinking logically. You're just repeating what you've been told to believe.

 

[rabbiporkchop]

You don't even know what the "other procedure" is because were talking hypothetically about an amplifier that has some kind of problem. Might be cheaper to fix the amp than buy some overpriced magic jumpers. Youre not thinking logically. You're just repeating what you've been told to believe.

Speaking from experience, choosing between $800 in labor to rebuild a DX1600x to function correctly or $75 for a null cable, most folks would prefer the cheaper route. I agree reconstructing an amp is preferable in my book. You seem to have overlooked the "consistently repeatable results" as the real reason for the jumpers and instead assumed it's a sales pitch for "overpriced magic jumpers".
Consistent repeatable results every time is reason enough to follow a standardized procedure.

 

[543_Dallas]

Speaking from experience, choosing between $800 in labor to rebuild a DX1600x to function correctly or $75 for a null cable, most folks would prefer the cheaper route. I agree reconstructing an amp is preferable in my book. You seem to have overlooked the "consistently repeatable results" as the real reason for the jumpers and instead assumed it's a sales pitch for "overpriced magic jumpers".
Consistent repeatable results every time is reason enough to follow a standardized procedure.

$800 bucks to repair an 8 pill that cost $900 from Copper Electronics or $75 for a coax jumper. As long as you think you got a good deal thats all that matters.

 

[rabbiporkchop]

$800 bucks to repair an 8 pill that cost $900 from Copper Electronics or $75 for a coax jumper. As long as you think you got a good deal thats all that matters.

They don't used beta matched transistors and they don't hone the bottoms for maximum heat dissipation.
I don't mind going the extra mile. Extra work doesn't come cheap. Might as well be building from scratch.

 

[undertaker]

Anyone who pays 65.00 for a jumper has mental issues!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[dave457]

www.dxengineering.com/search/part-type/coaxial-cable-assemblies/product-line/dx-engineering-rg400-high-isolation-coaxial-cable-assemblies?autoview=SKU&sortby=Default&sortorder=Ascending