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Author Topic: Palstar Commander HF-2500 Magunm  (Read 11406 times)
N6TA
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Posts: 13




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« on: December 06, 2009, 08:48:12 PM »

As I was preparing to upgrade from my old SB-220 and looking at Command Technologies, things got interesting and a bit confusing.  So, Palstar is in charge.  Fine.  They revised the design to improve it.  Great!  They added a model to the product line: the Magnum.  Per their website the magnum is different:
'The Commander HF-2500 MAGNUM is identical to the Commander HF-2500 except that the MAGNUM features a full-wave rectifier in the high voltage power supply, while the HF-2500 has a voltage doubler high voltage power supply.'
The price difference is about a thousand bucks.  Can someone tell me why the full wave is better by a grand?  The manual shows an increase in voltage.  Doesn't that mean a little different plate Z to match to?  I certainly do not need more soup, it that is the benefit of the higher voltage B+.

Regardless, still leaning towards a XMAS give to myself.
Al
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HFRF
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« Reply #1 on: December 06, 2009, 09:28:06 PM »

You are trying to analyze why the marketing dept. at Palstar does something.  Who knows their reasons?  Why don't you call Palstar and ask.  I am amazed at the number of questions that are asked in a forum when the manufacturer can probably give an accurate answer.  I get the impression people are afraid to call them. Why??
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W8JI
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« Reply #2 on: December 07, 2009, 05:13:39 AM »

If you gave any good engineer $1000 to work with a power supply of a given size and told him to use any rectifier system he wanted, he would have a very difficult time choosing between a doubler and a a full wave bridge.

This is because if someone spends the same money on both the results are almost identical. The doubler needs twice the peak current but you can use twice the gauge of secondary wire, so voltage drop is the same. There might be a tiny advantage because the transformer needs a little less insulation in the doubler, but basically they are the same.

When we did the AL12 amplifier series, we used a bridge because Hams liked the bridge better. They thought it would be a better supply. The truth is it could have been a doubler with identical results if the transformer cost and size was the same.

If someone is looking for a day and night difference it really isn't there unless the doubler had a smaller transformer or didn't have double the secondary winding copper thickness to go with the 1/2 turns used.

Tom

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K6AER
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« Reply #3 on: December 07, 2009, 09:15:46 AM »

There is more than just the full wave bridge involved on the Commander HF-2500 MAGNUM. The unit is upgraded to the pulse version of the 3CX800A7 which is the 3CPX800A7. The control boards and power supply board have been redesigned (thank God) and now have accurate schematics as well as legends on the PCB noting the actual components. The transformer is higher in voltage and current.

I looked at the unit at Dayton this year and Don Kessler, the new engineer, has done a nice job of dragging the old design into normal engineering practices used today.

Don told me he was adding a access door on the cabinet bottom so as to be able to access the HV power supply board. Make sure that has been done before you buy the amplifier. With out the access panel you have to dismantle the RF tank assembly to get to the bottom of the tube plenum to work on the power supply section. To recap a Commander HF-2500 takes about 5 hours of work.
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N6TA
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« Reply #4 on: December 07, 2009, 01:38:40 PM »

Thanks for the inputs.  
I note that the current webiste descsribes BOTH of the current HF-2500 units as using the pulse tube, not just the Magnum.  
http://www.palstar.com/commander_hf-2500.php

In my first post, I quoted from their site that the ONLY difference is in the rectifiers.  W8JI made some fine comments to consider as well.
Anyway, I have tried to call and get the constant busy signal and the email I sent is unanswered for the time being.  Not a problem.  I appreciate the positive comments about the update to the design.  I will ask about the access you mentioned.
Al
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W8JI
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« Reply #5 on: December 07, 2009, 05:22:21 PM »

Thanks for the inputs.  
I note that the current webiste descsribes BOTH of the current HF-2500 units as using the pulse tube, not just the Magnum.  
http://www.palstar.com/commander_hf-2500.php

In my first post, I quoted from their site that the ONLY difference is in the rectifiers.  W8JI made some fine comments to consider as well.
Anyway, I have tried to call and get the constant busy signal and the email I sent is unanswered for the time being.  Not a problem.  I appreciate the positive comments about the update to the design.  I will ask about the access you mentioned.
Al

Al,

Prices do go up sometimes. 3CX800's are going through the roof.

As for power supply only......I would not buy based in a full wave bridge but more on the style and weight of the transformer, if the filament winding is on its own transformer, and things like that.

They should have a no-load to full load voltage spec, and users should be able to give you an idea if any transformers have failed.

Tom
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N6TA
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« Reply #6 on: December 10, 2009, 09:00:13 PM »

I had a nice chat with Paul Hrivnak, the President and CEO at Palstar.  Paul is a very busy man but gave his time genereously to answer my questions.  My goal was to learn how the new Commanders differ from  the original Command Technologies versions run by Pat.  Some interesting info from the conversation:
All three models have had the PCBs revised.
Processor controls have been added to sensitive functions.
AC mains have fuses in both legs, not just one side.
Rectifiers have been upgraded
Filter caps are about 2X the prior value.
The single plate choke has been divided into two: one for 160&80 and the other for 40 thru 10 M.  They are switched by a vacuum relay.
Some toroids have been re-designed to get the ferrite temperature under control.
The step start is a real one in that relays switch short out a resistor after two seconds.
An access panel is added to allow access to the power supply board.
The AC mains cord is removable and a decent gauge cord is provided.  
Sheet metal around the transformer has been thickened and a new sheet metal supplier provides a fit that does not require and awl for alignment of holes.
The units are CE marked for importation to Europe.
Certain resistors have been improved.
I gathered that he could have continued to list changes.
The Magnum has a 3.1 kW transformer that is 16 lbs heavier.  The HV is 3.2 kV.  CW power is 2.5 kW vs 1.8 kW for the basic model.  The plate voltage change requires different impedance matching though this would not be a big deal.  Just differnet than the basic model.  The export version is 3.5 kW.

Paul is working '12 hour days' and the company is busy with a non-ham DHS contract.  However, amp deliveries are coming into focus with about 4 week delivery estimates.

I am not an expert but Paul certainly has improved the product.
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K6AER
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« Reply #7 on: December 11, 2009, 09:37:18 PM »

All though Paul Hrivnak is the President it was Don Kessler, their new engineer who redesigned the amplifier from the ground up and dragged the design into the 21st century. Given the amount of engineering put into the new design I am not sure why they bothered to buy the old company.
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WA9ZOH
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« Reply #8 on: December 13, 2009, 09:12:48 PM »

I don't understand it. I just checked to see if QRO Technologies was still in business and their web page is showing a update of Oct. 2009. How can they still be making them and Palstar as well?
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K6AER
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« Reply #9 on: December 13, 2009, 09:51:15 PM »

Palstar took over the Commander product line.

QRO is a different company.
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K2MK
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Posts: 407




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« Reply #10 on: December 14, 2009, 04:56:14 AM »

Command Technologies was owned by Pat Stein (Edon, Ohio) who retired in 2008 and sold out to Palstar (Piqua, Ohio).

QRO Technologies was and still is owned by Ray Connin (Bryan, Ohio).

Stein and Connin once worked together. Confusion is understandable.
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N6TA
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Posts: 13




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« Reply #11 on: December 14, 2009, 09:13:58 PM »

Confusion is predestined when two differnet brands come up with a similar design with the same model number: HF-2500.
Palstar came into the picture as a buyer when Pat of Command Technologies became ill.
Further confusion when the 'old' Command1.com website for Command Tech. has not re-directed to Palstar.  So, search for Commander or HF-2500 and you can get the old site, old spec sheet, old image of the amp that is no longer available.  I brought this to the attention of Paul at Palstar and he acknowledged that they are **busy** and that has slipped thru the cracks.
The Palstar acquisition is so new that even the Palstar dealers do not even know they have a new amplifier to sell.  I found out about that today when I was calling to ask for price and terms.
If you are serious about an amp of this price and capability, I guess you need to perservere to get to the truth.
Al
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WB0MCO
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Posts: 82




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« Reply #12 on: January 20, 2010, 11:28:16 AM »

"All though Paul Hrivnak is the President it was Don Kessler, their new engineer who redesigned the amplifier from the ground up and dragged the design into the 21st century. Given the amount of engineering put into the new design I am not sure why they bothered to buy the old company"Huh?

How can this be a 21st century design? No 17,12 meter
band switch, no 12,17 tuned input. And what's with
the ugly yellow faced meters?
Don't see anything about QSK,and uses outdated tubes.
I'll look elsewhere for my next amp.
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K6AER
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« Reply #13 on: January 20, 2010, 08:42:09 PM »

I’ll give you that the amplifier would look different with white meters but you are wrong on the other issues.

12 meters is tuned in the 10 meter position.

17 meters is tuned in the 15 meter position.

3CPX800a7’s are a current production tube and I might add have one of the lowest IMD numbers available. The tube is manufactured by no less than 4 different manufactures.

The amplifier is microprocessor controlled.

Have you call about the addition of QSK keying?

Out of curiosity what would be your first choice in a Legal ++ HF amplifier?
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KA3VVV
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« Reply #14 on: September 07, 2010, 07:45:32 PM »

Who repair the old command tec hf 2500. Palstar don't do the repair anymore.
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