HFU HF Underground

Technical Topics => Part 15 AM and FM Station Operation => Topic started by: ChrisSmolinski on January 18, 2020, 1150 UTC

Title: Part 15 MW Tansmitter Kit on eBay
Post by: ChrisSmolinski on January 18, 2020, 1150 UTC
$24 shipped from Thailand: https://www.ebay.com/itm/531-to-1602-kHz-Low-power-AM-PLL-transmitter-kit-for-learning/153799136672

It includes crystals for both 9 and 10 kHz channel spacing. From a review I read elsewhere, it puts out about 70 mW, and goes up to 1710 kHz.
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: ThaDood on January 18, 2020, 1751 UTC
NEAT!!!! And, if you want to build a Part #15 compliant antenna for this, Bob at MRAM1500, shows how to do this.   http://mram.us/AntennaStory.htm
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: flexoman61 on January 19, 2020, 1157 UTC
Bummer, says listing has ended.
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: Rob. on January 19, 2020, 1235 UTC
This seller restocks this item often so check back in a week or so.
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: ChrisSmolinski on January 19, 2020, 1313 UTC
This seller restocks this item often so check back in a week or so.

And there it is: https://www.ebay.com/itm/531-to-1602-kHz-Low-power-AM-PLL-transmitter-kit-for-learning/153801485438
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: purplesky on January 19, 2020, 1437 UTC
But beware. Output amplifier operates in Class C. Don't think about amplifying this thing
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: JimIO on January 19, 2020, 1543 UTC
It has 3 switch selectable low pass filters after the final. Amplify then high level modulation would be the way to go if you wanted more power.

~
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: Stretchyman on January 19, 2020, 1608 UTC
The 'way to go' would be to buy a proper transmitter in the first place!

I don't get this Part 15 thing?

70mW and you're trying to amplify it...why bother?

I ask you!

 ;)

Str.
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: ChrisSmolinski on January 19, 2020, 1615 UTC
The 'way to go' would be to buy a proper transmitter in the first place!

I don't get this Part 15 thing?

70mW and you're trying to amplify it...why bother?

I ask you!

 ;)

Str.

Some people want to run a legal Part 15 transmitter, to cover a small area, un-amplified. You're allowed 100 mW and a 3 meter antenna, so 70 mW is legal. Avoids getting The Knock  :)
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: TonyD on January 19, 2020, 1902 UTC
It is actually a cool little oscillator. Got mine in kit form a few years ago and it worked a charm. Check out..

https://www.amateurradioshop.nl/webshop/bouwkits/hf/detail/41/am-pll-middengolf-oscillator-bouwkit.html

Or just build your own.  http://www.tompolk.com/radios/frequencysynthesizer/freqsynth.html

There are a lot more schematics floating about for this. Must dig them out.

Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: N9QIW on March 14, 2020, 0406 UTC
I bought (and received) one of these kits from E-Bay.   Unfortunately,  no schematic was provided with the kit.  Does anyone have a link to a good schematic, pdf, etc?   
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: N9QIW on March 14, 2020, 0417 UTC
Cancel that.  I think this is the correct schematic: https://drive.google.com/file/d/12Yjb3Vw2Dr0Qa4AUOGLJELPkQlfi7KyV/view

Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: Teotwaki on March 20, 2020, 1323 UTC
NEAT!!!! And, if you want to build a Part #15 compliant antenna for this, Bob at MRAM1500, shows how to do this.   http://mram.us/AntennaStory.htm

It seems that url just needs the "WWW" to work:  http://www.mram.us/AntennaStory.html

I also ran across some related sites  8)

https://vk.com/realfreeradio
https://mbcf.boards.net/thread/315/question-mram-1500
Title: Re: Part 15 MW?
Post by: ThaDood on March 22, 2020, 1829 UTC
While you're on this Part 15 kick, here's another site,   http://boomerthedog.net/radio.html

Title: Re: Part 15 MW?
Post by: Teotwaki on March 23, 2020, 0324 UTC
While you're on this Part 15 kick, here's another site,   http://boomerthedog.net/radio.html

Thanks for that link! I really liked the low power AM transmitter in a box.

(http://boomerthedog.net/images/chez-uncovered-sm.jpg)
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: redhat on March 27, 2020, 0111 UTC
I got one of those Greek C-QUAM transmitters recently and will be doing a youtube video on it soon with partial stereo proof-of-performance measurements.  Its based largely on the Chris Cuff design.

+-RH
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: vblank on April 05, 2020, 0329 UTC
Thought I'd chime in... I bought this kit from eBay recently.
I''ll start by saying that I've actually designed and built several non-radio kits for my own business. I was unable to get this one running.

Engrish aside, the design is very interesting and easy to understand. 4 parts were missing, including a couple "irritating" to fine.
Once I sorted everything, I had a spot-on carrier with no modulation. I troubleshot the obvious culprits for a day, and them binned it.

I have no doubt that the design is worth the money, but missing parts from an overseas shipper suggests a certain level of "I don't care."
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: ka1iic on May 08, 2020, 2051 UTC
Why run pt. 15 ?  Well I do but I live in a heavily concentrated area home wise that is...  I use AM and FM and well let's see  8  5 unit apartments equals 40 + listeners... and that doesn't include the folks across the road, mostly older like myself but so many of us luv 'old radio shows'...  brings back memories of when we were much younger...  :-)

have a great day and a better tomorrow :-)
Title: Re: Part 15 MW Tansmitter Kit on eBay
Post by: Dave Richards on May 11, 2020, 1747 UTC
The eBay kit referred to in the original post on this thread has been out of stock for a while now. I messaged the seller to ask if he will be selling it again. He replied that the airlines in his country (Thailand) are not operating because of the COVID-19 situation and, therefore, he cannot sell his products.

Hopefully, it will be back in stock at some point in the future.