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Author Topic: CLASS-D- DDS-AM- TRANSMITTER- PWM-MODULATOR - 1.8MHz -3.5MHz-500W RMS-2KW PEP  (Read 11625 times)
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WB4AM
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« on: April 19, 2015, 11:44:58 AM »

Hello All,

Does anyone know if this is a good transmitter to purchase?

It takes 120 volts "DC"  to power it.  Seller claims two or more PC Server power supplies can be modified to achieve this type of voltages needed?  I have checked and there are such supplies out there to be used for Servers.

What I liked about this transmitter is the built in amp that will achieve legal limit.

I have a couple of SDR Radios that will get me on the low bands.  I also have a QRO amp for more output.  But with the use of the AM mode, as we all know it can be very hard on our amplifiers.  So I thought maybe this might be another avenue to try???

I read about the Super Senior and read from others that typically the transmitters output should be set at 300 watts out?
Also the designer of the Super Senior is now concentrating on a 75/40 meter version and I am assuming he doesn't have any Seniors in stock?

Anyway here is the link of the transmitter that I have viewed and I am curious what other have thought about it?
http://www.ebay.com/itm/151633197582?_trksid=p2060353.m1438.l2648&ssPageName=STRK%3AMEBIDX%3AIT

Thank you for your time and any helpful info along the way!

ken
   
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KF1Z
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Are FETs supposed to glow like that?


« Reply #1 on: April 19, 2015, 12:23:45 PM »

It's a crap shoot, unless you can find someone who has purchased the same unit.

The cost...  $760.  PLUS enclosure, PLUS power supply.

That's what, another $300 ? plus time to put it all in the enclosure etc.....


If you want it.....   MY opinion would be to contact K7DYY and ASK him if any Super-Seniors are available,
or how long the wait would be.
Get it from HIS mouth.... not the thoughts of others..  :-)

Yup, it's $1400 + shipping, but it's all enclosed, has it's own power supply built in,
and most importantly, there are quite a few people that already have one to get opinions from.


I can't tell just from the picture on the listing, but I think that design is floating around on a few sites on the web.



Really up to you, it could be a gamble, ( I'm pretty sure this fellow isn't going to refund you any money or offer to service it if there is a failure.)


That's my $0.05 worth





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WBear2GCR
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Brrrr- it's cold in the shack! Fire up the BIG RIG


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« Reply #2 on: April 19, 2015, 11:08:54 PM »


Support the Greek economy?

Seems like they are selling a bunch of solid state RF things out of Greece these days...

There may be other ways to go...

                                   _-_-
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_-_- bear WB2GCR                   http://www.bearlabs.com
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Patrick J. / KD5OEI
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« Reply #3 on: April 20, 2015, 04:17:04 AM »

I read the same somewhere that it is 300W, not 500. I would not believe inflated claims on something like that esp. coming from so far away..
If it's been run too hard, well.. people sometimes sell things of for a reason too. Do you have a way to check it right away upon receipt and does eBay protect you from goods that are not what they should be? Seems a risk.
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Radio Candelstein - Flagship Station of the NRK Radio Network.
WB4AM
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« Reply #4 on: April 20, 2015, 06:02:54 AM »

It's a crap shoot, unless you can find someone who has purchased the same unit.

The cost...  $760.  PLUS enclosure, PLUS power supply.

That's what, another $300 ? plus time to put it all in the enclosure etc.....


If you want it.....   MY opinion would be to contact K7DYY and ASK him if any Super-Seniors are available,
or how long the wait would be.
Get it from HIS mouth.... not the thoughts of others..  :-)

Yup, it's $1400 + shipping, but it's all enclosed, has it's own power supply built in,
and most importantly, there are quite a few people that already have one to get opinions from.


I can't tell just from the picture on the listing, but I think that design is floating around on a few sites on the web.



Really up to you, it could be a gamble, ( I'm pretty sure this fellow isn't going to refund you any money or offer to service it if there is a failure.)


That's my $0.05 worth





Thank you Bruce for your reply.  It helps to get an opinion from others.  I have emailed K7DYY directly and he did mentioned he was working on a 75/40 meter version.  The way I had inquired and the response that K7DYY had gave me, lead me to believe he doesn't have any of the Super Seniors in stock. 

But what you and others had mentioned here about the transmitter on Ebay, I am going to take everyone's advice and look else where.

Thank you all for your advice.  It was worth mentioning!

Ken



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n1ps
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« Reply #5 on: April 20, 2015, 08:21:42 PM »

Well I certainly would have more concerns with the Greek TX than the DYY TX by a wide margin Cool.  However the reports of late on the DYY TX have not been so good either with a lot of failures.  One ham up this way has sent his unit back several times (7 I think?).  I dont know why all the crap outs.  It could be site related such as SWR.  I dont like that the TX does not have any meters, especially to monitor drain currents.   I played with one here a few years ago.  We quickly realized it was best to run it at no more than 250 watts despite the claims of 400 watts.  On the other hand perhaps DYY will solve the issues in time.  I like that a commercial Class D/E rig is available.  The price is very good.  Id love to see a kit for the QIX designs.  Perhaps the 2-4 FET design gains ground there.  If you like class D, look at Jay W1VD's site. 

By its nature the D TX is less expensive than an E TX as there are fewer expensive tank components and smaller cases.  On the other hand you could hire a builder to make a E TX for you.  This is what Al W1VTP opted for with great results (see earlier thread with pics).  Bruce may be able to help you there.

My 2 cents...worth less than Bruce's 5 cents Grin Grin Grin

Peter
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steve_qix
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« Reply #6 on: April 20, 2015, 09:35:53 PM »

Pete brings up a good point.  You could have a rig built for you.  It will run higher power and definitely be more reliable than anything commercially available (that I know of) in the class D/E product space.

Something to think about, anyway.  There are several folks who build these types of transmitters on a reasonably regular basis.
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High Power, Broadcast Audio and Low Cost?  Check out the class E web site at: http://www.classeradio.org
flintstone mop
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« Reply #7 on: April 23, 2015, 06:54:09 PM »

Pete brings up a good point.  You could have a rig built for you.  It will run higher power and definitely be more reliable than anything commercially available (that I know of) in the class D/E product space.

Something to think about, anyway.  There are several folks who build these types of transmitters on a reasonably regular basis.

I never knew that!! Good info to remember. I would trust someone from AMFONE building a first class TX than something that can be trouble down the road. Someone did a 10 star rated job building Al's TX. really nice workmanship
Fred
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Fred KC4MOP
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« Reply #8 on: April 24, 2015, 09:55:09 PM »

<snip>

 On the other hand you could hire a builder to make a E TX for you.  This is what Al W1VTP opted for with great results (see earlier thread with pics).  Bruce may be able to help you there.

My 2 cents...worth less than Bruce's 5 cents Grin Grin Grin

Peter

Absolutely agree!!  I am totally satisfied with the result (thanks Wayne). 

Al
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