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Hardcord hams on QRZ

1iwilly

1iwilly

Sr. Member
Dec 7, 2008
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man them supper strictly hardcore ham guys on QRZ are rough they said it's a waste of time to use a Palomar 300A on 10 or 20 meters when the radio these days does 100 watts and the Palomar running it in clean mode is only 150 watts. here is the quote Being a 300W "Input" (As they were rated then), I would think you will only get about 150W out clean (As stated above) & not worth adding it to a rig already capable of 100W. When the rig is turned down to drive it, the efficiency & quality of the signal goes down.
#2-It does seem like too much risk for too little reward (+1.76 dB transmit power gain).
 

Havent logged into the QRZ forums which seems for quite some time. From what I understand, though the Palomar itself shows the different bands etc, it is mainly geared towards 10m. Was talked about I believe a few months ago about why it isn't a good idea to run a Palomar 350Z on other bands besides 10. Same might be for the 300A.
Also, unsure if that "when the rig is turned down to drive the amp, efficiency and quality of the signal goes down" is the case. Does this mean if you turn down a radio to output 15 watts and feed it into lets say an Elecraft KPA-1500, your signal will sound bad?? :)
 
doffo said:
Havent logged into the QRZ forums which seems for quite some time. From what I understand, though the Palomar itself shows the different bands etc, it is mainly geared towards 10m. Was talked about I believe a few months ago about why it isn't a good idea to run a Palomar 350Z on other bands besides 10. Same might be for the 300A.
Also, unsure if that "when the rig is turned down to drive the amp, efficiency and quality of the signal goes down" is the case. Does this mean if you turn down a radio to output 15 watts and feed it into lets say an Elecraft KPA-1500, your signal will sound bad?? :)
Click to expand...
i had an amp builder fix the 20-meter band for me that's usually where I talk. on the low side, 35 watts drive from the radio got it back last night this morning made contact with NJ I was told the audio was up and the signal compare to just the 100 watts from the radio
 
AudioShockwav said:
27 mhz is a dirty word on the zed.
11 meters is a sore spot on the zed.
CB is a no no on the zed.

That is all

73
Jeff
Click to expand...
This was my question =
pick up a Palomar 300A with 8 extra sets of tubes. is 40-watt drive on low for 20 meters about right ??
don't want to overdrive the tubes using FT-890. Or can I lower the carrier to 5 watts and use it on the high side?
 
doffo said:
Same might be for the 300A.
Click to expand...
It has a bandswitch on the output circuits only.

The input to the amplifier is tuned for 10 or 11 meters only. A radio driving it on the other bands will show a sky-high SWR on the amplifier's input, and very little drive power will reach the tubes. The difference between 10 and 11 meters is only the position of the screw on two trimmer caps. One for low side, one for high side. The adjustment range of those trimmers usually covers either band, but not both at once terribly well.

Using the bands below 10/11 meters will call for new input circuits tuned for the band of interest. There is no mechanically practical way to switch input circuits for multiple bands, so you'll be stuck with modding it for one band.

73
 
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i tried it on 20 meters last night the input between the radio and amp was adjusted to the lowest which ended at 1.5 SWR. The input trimmer was put in place of the receive switch for easy access when only the low side is used. also, more capacitance was added for the tunning range. with 40 watts drive for testing purposes on 20 ssb talking between 280 to 300. the question still remains is it ok to run this amp this way
 

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It's okay until somebody with a SDR waterfall display tells you you're showing up on too many frequencies.

Keeping the drive level where you have it will probably prevent that kind of trouble.

Excellent hack! Congrats.

Oh, and when the plug-in relay board takes a dump, we have replacements listed on fleabay.

73
 
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nomadradio said:
It has a bandswitch on the output circuits only.

The input to the amplifier is tuned for 10 or 11 meters only. A radio driving it on the other bands will show a sky-high SWR on the amplifier's input, and very little drive power will reach the tubes. The difference between 10 and 11 meters is only the position of the screw on two trimmer caps. One for low side, one for high side. The adjustment range of those trimmers usually covers either band, but not both at once terribly well.

Using the bands below 10/11 meters will call for new input circuits tuned for the band of interest. There is no mechanically practical way to switch input circuits for multiple bands, so you'll be stuck with modding it for one band.

73
Click to expand...
Ahhh. You were the one who mentioned that in another thread some months ago. :) Thanks for the explanation.
 
nomadradio said:
It's okay until somebody with a SDR waterfall display tells you you're showing up on too many frequencies.

Keeping the drive level where you have it will probably prevent that kind of trouble.

Excellent hack! Congrats.

Oh, and when the plug-in relay board takes a dump, we have replacements listed on fleabay.

73
Click to expand...
the amp builder was thinking ahead. every time I stepped on it last night I thought I was running a cx3000A box LOL
 

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9C1Driver said:
After looking at your pic you might check this article out and compare fig 1 & 2 to your ground pipe deal on the wall.

https://helpdesk.flexradio.com/hc/e...n-the-Ham-Shack-Paradigms-Facts-and-Fallacies
Click to expand...
That is an excellent article ! That should be mandatory reading for every ham and every 11 meter op as well.
My setup is on the ground floor of a shop building. 2 six foot ground rods, 4 foot ground cable through the wall to a single point bus bar.
I ground my rig, amp, and an antenna tuner if I am using one. I also ground my Megawatt power supply as it shunts any switching noise to ground.
SWR meter has a ground lug on the back but I don't use it.
 
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