Who's the best?

[NightThumper]

Ranch55 said: “Icom PW-1 to operate on 11 meter requires removing one surface mount diode..... that's all. And I do understand that this is some information you are not interested in. Just sayin' ......”


I”ll have to remember that the next time I purchase a solid state amp. My Palstar LA-1K would not operate on 11 meters so I sold it...but this baby sure does...Acom 2000P

 

[kopcicle]

 

[SIX-SHOOTER]

Icom PW-1 to operate on 11 meter requires removing one surface mount diode..... that's all.
And I do understand that this is some information you are not interested in.
Just sayin' ......

I removed that super small part the day I got it or it would not operate on 10 or 12 meters either but I won't be using it on 11 meters.

SIX-SHOOTER

 

[Shockwave]

Since the original poster already has a 1X4 Davemade, why not just bypass the first transistor driver in that amp and drive it with the 50 watt PEP radio? The current it draws will drop down and it should loaf at the 250 watts he is looking for with ample headroom on positive peaks. Adjust the drive for desired current and output.

With respect to the PW-1, that is a great amp but consider getting a good quality surge protector for its power supply and unplugging it when not in use. The switching power supply is susceptible to voltage spikes, resulting in cracked toriodal cores. According to Icom, they have no access to replacement parts as this supply is manufactured by a third party. Any failures here require a complete replacement of the supply at an astonishing cost.

 

[kopcicle]

why not just bypass the first transistor driver

remember that the series input impedance is about .938-j .201
and parallel equivalent input impedance is 1.06 ohms across 1800pf @ 30 mhz
(Taken directly from AN762 Motorola)
For all practical purposes you can use 2 ohms as a target impedance.
That becomes 2 ohms divided by four when the driver is bypassed.
A 50 ohm input attenuation/termination ahead of either a tuned network or broadband transformer is required to drive the 4 transistors.

 

[SIX-SHOOTER]

Since the original poster already has a 1X4 Davemade, why not just bypass the first transistor driver in that amp and drive it with the 50 watt PEP radio? The current it draws will drop down and it should loaf at the 250 watts he is looking for with ample headroom on positive peaks. Adjust the drive for desired current and output.

With respect to the PW-1, that is a great amp but consider getting a good quality surge protector for its power supply and unplugging it when not in use. The switching power supply is susceptible to voltage spikes, resulting in cracked toriodal cores. According to Icom, they have no access to replacement parts as this supply is manufactured by a third party. Any failures here require a complete replacement of the supply at an astonishing cost.

Since the original poster already has a 1X4 Davemade, why not just bypass the first transistor driver in that amp and drive it with the 50 watt PEP radio? The current it draws will drop down and it should loaf at the 250 watts he is looking for with ample headroom on positive peaks. Adjust the drive for desired current and output.

With respect to the PW-1, that is a great amp but consider getting a good quality surge protector for its power supply and unplugging it when not in use. The switching power supply is susceptible to voltage spikes, resulting in cracked toriodal cores. According to Icom, they have no access to replacement parts as this supply is manufactured by a third party. Any failures here require a complete replacement of the supply at an astonishing cost.

I have an MFJ surge protector but I never unplug the PW-1 where it has been plugged in since 2013 when my wife gave it to me as a retirement gift.

SIX-SHOOTER

 

[Slowmover]

I have an MFJ surge protector but I never unplug the PW-1 where it has been plugged in since 2013 when my wife gave it to me as a retirement gift.

SIX-SHOOTER

Seems a fair trade for returning her red panties.

 

[543_Dallas]

remember that the series input impedance is about .938-j .201
and parallel equivalent input impedance is 1.06 ohms across 1800pf @ 30 mhz
(Taken directly from AN762 Motorola)
For all practical purposes you can use 2 ohms as a target impedance.
That becomes 2 ohms divided by four when the driver is bypassed.
A 50 ohm input attenuation/termination ahead of either a tuned network or broadband transformer is required to drive the 4 transistors.

The dave style amps with drivers are the same as one without a driver. The input to the 4 pill section should be 50 ohms. There is a combiner and tuning cap on there already. The input tuning cap is a 270pf if im not mistaken.

All he should have to do is disconnect the driver stage from the 4 pill, remove the mini coax from the variable and connect it to the input of the 4 pill. It would also be a good idea to disconnect the b+ from the 1 pill driver. Not really necessary with a class C amp but it doesn't hurt.

 

[kopcicle]

There is a combiner and tuning cap on there already.

A 50 ohm input attenuation/termination ahead of either a tuned network or broadband transformer is required to drive the 4 transistors.

 

[543_Dallas]

A 50 ohm input attenuation/termination ahead of either a tuned network or broadband transformer is required to drive the 4 transistors.

I agree. It is required. All I'm saying is that it's already there in the davemade that shockwave was talking about and copies of the davemade. You can bypass the final section and run only the driver or bypass the driver and run only the final. Some guys have installed reays to switch them on the fly.

On 6 pill and larger amps you have either 2 pill sections or 4 pill sections with splitters and combiners. You can isolate each section and test them individually when troubleshooting. It's a very simple design.

 

[Shockwave]

Most of the time these amps have an excellent input VSWR right at the input splitter, after adjusting the trimmer capacitor. I think Kopcicle was thinking we would be directly driving the base inputs to the finals but we are still in front of the input RF transformers that step the drive impedance way up.

Having said that, good RF design will always use a input matching circuit in front of the first RF splitter. Not only does it insure a perfect 50 ohm input, it also makes the amplifier run cleaner. Especially when using a tuned input circuit which is very easy to do on a narrow band amplifier. You just add a small coil and one more trimmer cap at the input. That also forms a low pass filter.

 

[rabbiporkchop]

according to you. sorry i dont have much faith in you and what you say

Perhaps you might value the opinion of a lead mechanic or shop supervisor of your local Ford, Chevy, or Dodge dealer more than my worthless opinion. All of them will concur that Snap On tools are vastly superior to Wal-Mart tools. Don't take my word for it. Ask your mechanic.

 

[kopcicle]

wtf
Let's review..

Who's the best amp builder?
And why?

Fair enough question and a few good responses.

Somewhere along the way there is the inevitable thread drift and we end up at ...

Snap On tools are vastly superior to Wal-Mart tools

wtf

 

[TheRealPorkchop]

True. Happens almost every time doesn’t it?

I will agree that Snap-On tools are better than Wal-Mart tools but I don’t use either, I’m a Kobalt or Craftsman guy myself. I do have a pile of high dollar tools but my regular ole tools out weighs them.

Maybe this thread is secretly about the tools used by the elite amp builders? Maybe all the DaveMades and X-Force boxes are assembled with Snap-On, Matco and Mac tools? The others such as BBi, Gatekeeper and the like are assembled with K-Mart type tools? Hahaha.

It’s a thread that’s been derailed by a sinister force that’s unseen to secretly spread the knowledge to the unknowing. A hidden entity, hidden behind the mask of a common user, trying to alert us to our wrong doings of spending money on overpriced amplifiers. The proverbial mole I guess you could say?

I think it’s trying to tell us to buy what you can afford but don’t spend your money unnecessarily when you can build your own. Or maybe it’s just someone who has a day job as a Snap-On rep and they’re drumming up business? Or maybe it’s just that damn Walmart trying to get our money just in time for Christmas??

 

[Handy Andy]

The answer to "The Best" when it comes to Amp build is not out there...

But 4 out of 1,456,231 others - feel Snap On Trolls is better than Wal-Mart tools...