Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: Prev 1 [2] 3 4 Next   Go Down
  Print  
Author Topic: Looks Like someone has finally come up with a Cheap and Proper SS AMP Kit  (Read 18830 times)
KD8MJR
Member

Posts: 5532




Ignore
« Reply #15 on: May 25, 2015, 12:02:19 AM »

This looks like a cartoon looking for a buyer.  I would not buy anything until I see the assembly manual. Even if it is a real kit it would require certification buy the FCC. The KPA-500 kit has the RF deck prebuild to pass FCC regulations. Your transistors will run $300 for MRF-150's. A 600 watt amplifier will run you $800 in parts including the power supply.

There are no cheep amplifiers in the universe.

While I agree with you that it's not an easy choice without seeing the assembly manual I don't think that kits like this require FCC approval, at least that's what I remember hearing.

To your second point, I think your getting the amps mixed up, the one on eBay is his new design that uses SD2933 and can do 800W but he seems to be going back and forth saying its 600W at other times.  He states that you DO get the four SD2933 finals in the kit, that's $500 worth of finals right there and that makes me scratch my head as to how he can be selling it at this price!
The only thing he implies is not included is the heatsink and the switching PS module plus the $35 worth of switches which he sells separately.  The confusing thing is that he is not making all of it 100% clear, he would be well served to post on eBay a list of parts that you are not getting and need to buy separately and therefore make it less Vague. BTW The PS module is $192 on Mouser.

If the only items needed are those three items this Amp should still be a Sub $1000 Amp with autoband switching.  Heck if it really does have 4x SD2933 included it would be worth it just to have them as spares for my Tokyo HY-Power 1.2Kfx.

73s
Rob
Logged

“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
W5RUM
Member

Posts: 13




Ignore
« Reply #16 on: May 25, 2015, 06:22:53 AM »

I agree with Rob.....I have  been associated with Amplifier manufacturing for many years.. If you have any knowledge on what quality parts cost.. there is absolutely no way can any one offer a kit for $400 using OEM SD2933 devices.. It's simply ludicrous..  Most Ham's have no clue on the engineering and manufacturing costs involved, even for a kit....An authentic STMicroelectronics SD2933 device costs $110+ each... Check with Mouser or Digikey....The price of just those 4 devices exceeds the price of the kit!... What you'll get for your  $400 is most likely,  a half equipped kit littered with Chinese knockoff parts... The old saying "You get what you pay for" in this case, is a very valid statement.. Adding the suggested switching power supply ($200) which is not included ..will increase the kit price by 50%...
« Last Edit: May 25, 2015, 06:26:44 AM by W5RUM » Logged
W9GB
Member

Posts: 3368




Ignore
« Reply #17 on: May 25, 2015, 08:19:10 AM »

FCC Part 97.307. Emission standards

  (d) For transmitters installed after January 1, 2003, the mean power of any
       spurious emission from a station transmitter or external RF power amplifier
       transmitting on a frequency below 30 MHz must be at least 43 dB below the
       mean power of the fundamental emission.
=====
IF you DIY Build, Build a Kit, or purchased Ready-to-Run appliance, the Emission standards are the same.  
You speak of FCC approval, but that is for Ready-to-Operate equipment and Assemble Kits (not kit of parts).  Regardless, you are still bound by the Part 97 Rules.  
Logged
N3QE
Member

Posts: 5575




Ignore
« Reply #18 on: May 25, 2015, 10:14:01 AM »

To your second point, I think your getting the amps mixed up, the one on eBay is his new design that uses SD2933 and can do 800W but he seems to be going back and forth saying its 600W at other times.

And at least once in that auction description "Max 900W Pout".

"Those pictures only for imagination and the amplifier is not shipped with kit." (But I think he's talking about an enclosure). The use of the subjunctive several times in the description may be correct usage to weasel out of selling something that is not a working amplifier kit, or it may just be poor Engrish and you do get a full kit.

A different auction auction by the same seller does not come with transistors, but can do "1000W", and the board is labeled "1.2kW": http://www.ebay.com/itm/PA-Unit-1000W-PEP-Linear-Amplifier-DN-600-4x-SD2933-VRF2933-SD2943-MRF150-/141674800033?pt=LH_DefaultDomain_0&hash=item20fc79e3a1

It's pretty clear that in that other auction, there are no PA transistors included in that particular item.
« Last Edit: May 25, 2015, 10:24:19 AM by N3QE » Logged
KC4MOP
Member

Posts: 960




Ignore
« Reply #19 on: May 25, 2015, 10:39:01 AM »

I think the folks who are posting and casting doubt on this "kit" bring some thinking to the table. Is it too good to be true? Is it really a complete kit?? and if assembled correctly, it works?
The schematic is on an included CD. The Russian seller mentions that a transformer is $35.00. Is that to complete the power supply or what?
I agree about the VAGUE description and the problems in that neck of the woods.
Are there any youtube vids of a working unit, describing the operation of this amp?  If it were a real deal; I would think that there would be some reviews or videos of working DN 600 amps.
This is a very good thread.
Thanks
Well shut my mouth!!
A Youtube link
https://www.youtube.com/watch?v=vM09wo7bmCY

and another one

https://www.youtube.com/watch?v=ajeX_hU7hvo

All in Russian, of course. Still a mystery
Fred
« Last Edit: May 25, 2015, 10:45:40 AM by KC4MOP » Logged
KM1H
Member

Posts: 5078




Ignore
« Reply #20 on: May 25, 2015, 10:48:17 AM »

I suggest a few of you practice reading comprehension.  Here is a bit more info on what the kit costs WITH the power transistors.

Carl



Announcement of the transistor amplifier DN-600.

Account the interests of the amplifier. Since 2013 it is proposed grade amplifier transistors MRF150. The amplifier is equipped with only the original transistors company STMicroelectronics, USA - SD4933. It is twice more powerful transistors compared with MRF150 (300W versus 150W) and the main "chip" SD4933 is that the plant manufacturer guarantees serviceability at transistor mismatch with the load of 20: 1.
Details of the SD4933 can be downloaded from the website of the manufacturer, the link => LINK
Amplifier output power ranges up to 24MHz over 700W. Maximum up to 900W range 40-20m.
For details on the amp in this configuration can be found in the forum link => LINK
The cost of DN-600 staffed SD4933 - eq. 1520 $. For those interested in the DN-600 with MRF150 (option $ 1200) - Implementation of such a version of the amplifier is not excluded - make a request. As an intermediate cost model (eq. $ 1,400) - Acquisition transistors SD2933.

Logged
KD8MJR
Member

Posts: 5532




Ignore
« Reply #21 on: May 25, 2015, 11:25:44 AM »

I suggest a few of you practice reading comprehension.  Here is a bit more info on what the kit costs WITH the power transistors.

Carl



Announcement of the transistor amplifier DN-600.

Account the interests of the amplifier. Since 2013 it is proposed grade amplifier transistors MRF150. The amplifier is equipped with only the original transistors company STMicroelectronics, USA - SD4933. It is twice more powerful transistors compared with MRF150 (300W versus 150W) and the main "chip" SD4933 is that the plant manufacturer guarantees serviceability at transistor mismatch with the load of 20: 1.
Details of the SD4933 can be downloaded from the website of the manufacturer, the link => LINK
Amplifier output power ranges up to 24MHz over 700W. Maximum up to 900W range 40-20m.
For details on the amp in this configuration can be found in the forum link => LINK
The cost of DN-600 staffed SD4933 - eq. 1520 $. For those interested in the DN-600 with MRF150 (option $ 1200) - Implementation of such a version of the amplifier is not excluded - make a request. As an intermediate cost model (eq. $ 1,400) - Acquisition transistors SD2933.

Carl I don't know where you got that information, maybe the forum.
No matter, it's what he says in the auction that counts and he clearly says:

Quote
You get a set of parts for self building of this amplifier.

KIT HF power amplifier Solid State DN-600 consists of parts:

1. Enclosure (in a set resistor 10W + stabilizers 24V, 12V) - steel, black

2. Copper plate

3. KIT PA Unit 4x SD2933 (Max 900W Pout). Consists of: 1.PCB SMD components soldered, 2.Ferrites, 3.Power resistor,
4.Transistors, 5.Trimmers R (as in the photo above).

4. KIT LPF600 Unit. Consists of: 1.Transformer T1; 2.Trimmer capacitor 4-20pF C16; 3.Trimmers 7pcs; 4.ECAP 2pcs;
                                                        5.Pelay K16 1pcs; 6.Transistors VT1, VT2, VT3 - 3pcs; 7.PCB LPF600 SMD components
                                                         are soldered; 8.Mica capacitor C3; (as in the photo above).

5. RF shield sheet between PA and LPF

6. PCB Input ATT unit (SMD components soldered - as in the photo above)

7. PCB Front indication PCB unit

8. PCB Step-Start Unit for SE-1000-48

Now that seems pretty clear to me that those are the parts that are included.

73s
Rob

« Last Edit: May 25, 2015, 11:42:06 AM by KD8MJR » Logged

“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
KD8MJR
Member

Posts: 5532




Ignore
« Reply #22 on: May 25, 2015, 11:31:11 AM »

Just to clarify something, he seems to have two versions of the PA board.  One uses 4x MRF-150s Which would make it capable of 600W max and the other uses 4x SD2933 which would make it a 1200W max PA board (Same configuration as what is in the Tokyo hy-power 1.5Kfx) His limitation seems to be the power supply which limits the amp to 800W.

I would also say in his defense that if he is using Google to translate, it could explain a lot!
If you want to get a good Laugh, use google to translate an English sentence into Japanese then use your mouse and copy the Japanese translation and paste it back into google and have it translate it back into English. You will find it's bloody awful even with simple sentences.
I spent two hours trying to get one paragraph to come out right trying all kinds of different phrasing and then gave up.  I sent an email with it in English to a friend who speaks and writes in both languages and asked him to type it up for me in Japanese.



73s
Rob
« Last Edit: May 25, 2015, 11:41:09 AM by KD8MJR » Logged

“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
KM1H
Member

Posts: 5078




Ignore
« Reply #23 on: May 25, 2015, 12:58:44 PM »

I dont think there is a mistake in the price on his web page, $1520 with the SD4933's and $1200 with the MRF 150's; the auction is very confusing and can be interpeted several ways. At Mouser the SD's are about $125 each.

Too bad my GF is away on business as she is a native Russian and now a US citizen. My #2 son is fluent also but lives in Germany and catching him long enough to translate the entire web page on that amp might be a problem.

Run the 150's at 600W as in the ALS-600 and you will sound just as bad. OTOH Kenwood runs a pair at 150W in the old TS-950SD and the IMD 3 is in the -40's.

Carl
Logged
N7EKU
Member

Posts: 1036




Ignore
« Reply #24 on: May 25, 2015, 02:06:15 PM »

Hi,

I see somebody asked on the eBay auction page, and the answer was that the kit does not include the PA transistors.

Anyway, if you read the list of parts included, for the PA board it does say transistors, but also says "as in the photo above".  The photo shows no PA transistors so the description is refering to the other transistors on the board (biasing etc.)

He does seem to know what he is doing, with attention to fan noise,  soft starting, PS RFI, and SWR protection.  It would be most important to know IMD figures I think.

73,


Mark.











Logged

Mark -- N7EKU/VE3
KD8MJR
Member

Posts: 5532




Ignore
« Reply #25 on: May 25, 2015, 03:36:12 PM »

Mark I am truly confused. I am reading his reply to that question and he says:

Quote
KIT HF power amplifier Solid State DN-600 consists of parts: 1. Enclosure (in a set resistor 10W + stabilizers 24V, 12V) - steel, black 2. Copper plate 3. KIT PA Unit 4x SD2933 (Max 900W Pout). Consists of: 1.PCB SMD components soldered, 2.Ferrites, 3.Power resistor, 4.Transistors, 5.Trimmers R (as in the photo above). 4. KIT LPF600 Unit. Consists of: 1.Transformer T1; 2.Trimmer capacitor 4-20pF C16; 3.Trimmers 7pcs; 4.ECAP 2pcs; 5.Pelay K16 1pcs; 6.Transistors VT1, VT2, VT3 - 3pcs; 7.PCB LPF600 SMD components are soldered; 8.Mica capacitor C3; (as in the photo above). 5. RF shield sheet between PA and LPF 6. PCB Input ATT unit (SMD components soldered - as in the photo above) 7. PCB Front indication PCB unit 8. PCB Step-Start Unit for SE-1000-48 Description see the link => http://www.qsl.net/ut2fw

Once again avoiding the guys question and Not giving a clear list of what is Not included.

BTW I don't see his reply as a clear statement since under #4 he says again "Transistors".  He must be talking about other transistors on the board.  At this point I am just going to assume that he is selling a Complete metal case and the PCB board plus a few other cheap SMD components and resistors etc.  Therefore one would have to spend at least another $700 - $900 to make it complete.
If this amp had better documentation it might be worth it but with the already fuzzy communication and lack of English documentation it seems like a very risky purchase.

It's kind of sad when someone goes to all this work and then falls short because they don't have clear documentation.  With good documentation and a 100% complete kit he could have carried a few dozen of them to Dayton and probably have sold them all if the price was close to $1200.  As it stands now your much better off buying an FL-7000 for around the same price.

Update:
Ok looked at his QRZ post and added up everything and without the heatsink and some other smaller parts that he does not specify it comes to $1408.  This is easily going to be a $1600 Kit


73s
Rob
« Last Edit: May 25, 2015, 04:05:31 PM by KD8MJR » Logged

“A lie can travel half way around the world while the truth is putting on its shoes.”  (Mark Twain)
KC4MOP
Member

Posts: 960




Ignore
« Reply #26 on: May 25, 2015, 04:24:11 PM »

I think with the replies I am reading now, that it would be good that I make a sharp U-turn and forget that I ever saw the listing in eBay. I even commented on his youtube vid that his eBay listing is extremely confusing.
Fred
Logged
W9GB
Member

Posts: 3368




Ignore
« Reply #27 on: May 25, 2015, 06:00:23 PM »

Elecraft KPA500-K, 500W Linear Amplifier, Kit. $ 2,099.95 ($ 2,299.95 assembled)

ACOM 600S, 600W Linear Amplifier.  $2,794.95
ACOM 1000HF, 1,000W Linear Amplifier (4CX800 tube). $ 2,799.95

Ameritron ALS-600, 600W Linear Amplifier.  $1,599.00
Ameritron ALS-1306, 1,200W Linear Amplifier,  $ 3,299.00
Logged
N7EKU
Member

Posts: 1036




Ignore
« Reply #28 on: May 25, 2015, 06:52:01 PM »

Hi Rob,

You must have missed the first part of his eBay answer:

Question & Answer    Answered On
Q:     Does this include the four SD2933 transistors?    May-25-15
A:     without SD2933

Wow that is quite the total price.  Ouch!

It was interesting to read all his description though.  Seems he really had a fight with Soviet RF transistors :-p  

73,


Mark.
Logged

Mark -- N7EKU/VE3
4X6HP
Member

Posts: 6


WWW

Ignore
« Reply #29 on: May 25, 2015, 11:17:13 PM »

I know this guy personally.
He does not speak English. And using Google Translate services to translate some text.
I will try to help you, will ask him questions posted here and will post here his answers.
Logged
Pages: Prev 1 [2] 3 4 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!