The Polar Explorer – A High-Efficiency Transmitter

Discussion in 'General Announcements' started by K1KP, Apr 17, 2019.

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  1. AB6RF

    AB6RF Ham Member QRZ Page

    Hi Tony, very interesting project!
    About time someone advances the technology on the TX side of ham radio..

    Can you explain more about the TX audio routing?
    Many modern transceivers have very flexible and well executed audio shaping features (equalizer, BW control, compressions..) and I agree that being able to still take advantage of those features would be nice.
    How does the TX audio processing of the main transceiver can be used in conjunction with the Polar Explorer transmitter?

    Mikko
     
  2. WN1MB

    WN1MB Ham Member QRZ Page

    Are you saying that the Polar Explorer as designed today will only work with an exisiting transceiver and not with just a receiver?
     
  3. K1KP

    K1KP Ham Member QRZ Page

    The Polar Explorer is currently under development and is a 'Works in Progress'. As such it has not committed to a final design.

    Compatibility: The current software development path is oriented towards control via an external transceiver. The Polar Explorer uses Hamlib, the same software package as WSJT, to provide compatibility with just about any transceiver/receiver that has a computer interface. I have had several inquiries about making it a true stand-alone transmitter, with a VFO knob, so it would work with non-computerized radios (think 75-4, etc). The good thing is that it is still in development and changes can be made to suit market demand.

    Transmit Audio: The mic and key plug directly into the Polar Explorer, which handles all audio processing as well as providing a built-in CW keyer. Current processing options include CESSB compression, which is a highly effective method for increasing average power. In this mode, audio bandwidth is standard SSB bandwidth of 2500Hz. If compression is turned off, bandwidth is opened up to 5kHz such as for AM. There are plans to include transmit equalization as well.

    -Tony, K1KP
     
  4. WN1MB

    WN1MB Ham Member QRZ Page

    deleted by WN1MB
     
    Last edited: May 24, 2019
  5. K1KP

    K1KP Ham Member QRZ Page

    I think you made an assumption that it has no frequency generating circuitry, but it does.

    It is a complete transmitter, with built in frequency generation. It is NOT an RF amplifier, and require no RF signal from the transceiver to transmit. If there is a receiver with a computer interface that is supported by Hamlib, then the Polar Explorer will work with it.
     
  6. WN1MB

    WN1MB Ham Member QRZ Page

    Thank you. That was a long walk for such a short distance.

    I deleted my post so as not to spread any misinformation.
     
  7. AJ4GQ

    AJ4GQ Ham Member QRZ Page

    Ok, I think I understand why none of those easily measured values are available because this project is not far along enough yet to have a fully functional working prototype.
    Let's explore some market realities before this goes any further.
    1. Comments on this site indicate little acceptance and a lot of scepticism about a transmitter and 500W PA in a box that requires the use of an existing transceiver. Most everyone already has a transmitter as part of their transceiver and, for the most part,
    see no benefit in purchasing another one as part of a 500W PA.
    2. The existing equipment suppliers such as the big three plus Flex, Elecraft, etc. have deep pockets and substantial footprints in the marketplace and going head to head with them seems foolhardy. Ergo, eliminate the idea of adding a Receiver or competing with them with a transmitter.
    3. Your stated expertise is in the PA. Capitalize on that and develop and build a 500W to 600W stand alone PA that provides easily understandable and verifiable user benefits that are sufficient to overcome the 600W AL-811 $820 price point. And/or, at a substantially higher price point, benefits that exceed the KPA500's.
    4. You've been stressing "High Efficiency". Wonderful. How does that add user value? So what if a user's electric bill goes down by $5 or $10 a month using your amp vs an AL-811 or KPA500?
    5. Some of us are wondering if the Polar Explorer is a solution to a problem that doesn't exist.
     
  8. K1KP

    K1KP Ham Member QRZ Page

    A fully functioning prototype exists and has been used to make hundreds of contacts on the air. Just because the software or final specifications are not yet finalized does not mean it does not exist. The user value is clearly described in the second line of my original post:

    "The Polar Explorer seeks to reduce the cost, size, and weight of mid-power HF transmitters".

    It has demonstrated the ability to do that by delivering 500W in a package that is half the weight of the Elecraft KPA500, the ACOM 600s, and less than half the weight of the AL-811 or the ALS606S. You can combine the Polar Explorer with a KX3 and have a complete 500W station for under 15 pounds - no other combination of transceiver and amplifier can claim that.

    It's OK if some people don't 'get it'. It is disruptive technology, and as such, may not be readily accepted by mainstream users. That's the same challenge that CW faced when it overcame spark; that transistors faced when they overtook vacuum tubes, and that SSB faced when it overcame AM. The response when meeting hams face-to-face at Dayton this past weekend says it won't be that hard for folks to recognize the advantages and adopt the new technology, once they understand the benefits it brings.
     
    KA0HCP likes this.
  9. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    1. Smaller PA
    2. Lighter weight
    3. Less heat in shack
    4. Quieter cooling fan/less need for audio gating/expander
     
  10. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    You don't get it.

    Strapping a Class D, Pulse Width Modulation amplifier onto a regular transceiver gives up many of the advantages of an integrated transmitter.

    -Tony isn't pitching investments for a new company.
    -He isn't competing with existing commercial products in price, or any other manner.
    -If you aren't a home brewer, this isn't for you.
     
    Last edited: May 24, 2019
    AB6RF likes this.

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