1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
    Dismiss Notice
Dismiss Notice
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.

667v high swr decreases with modulation

Discussion in 'CB and Export Equipment and Accessories' started by 86lidewell, Apr 27, 2021.

  1. 86lidewell

    86lidewell Active Member

    Joined:
    Oct 10, 2020
    Messages:
    138
    Likes Received:
    163
    antenna analyzer: SWR is flat on 27205 with a bit more on ch1 and 40
    monitoring 667v with cross needle meter between amp and antenna 667v swr can go to 3:1 at full power.
    modulation brings SWR down to 1:1 like watching PEP swing.
    various other amps no SWR issue



    what could this be? (did a search)
    667v is one of the nasty DEI pill models from last year.
     

  2. sp5it

    sp5it Master of puppets

    Joined:
    Jul 9, 2009
    Messages:
    1,912
    Likes Received:
    2,167
    Parasitic oscillation. Send it back. I had similar problem with 667.
    Mike
     
  3. 86lidewell

    86lidewell Active Member

    Joined:
    Oct 10, 2020
    Messages:
    138
    Likes Received:
    163
    copper electronics :(
     
  4. 86lidewell

    86lidewell Active Member

    Joined:
    Oct 10, 2020
    Messages:
    138
    Likes Received:
    163
  5. sp5it

    sp5it Master of puppets

    Joined:
    Jul 9, 2009
    Messages:
    1,912
    Likes Received:
    2,167
    Yes, this amp. Went back to the store.
     
    86lidewell likes this.
  6. 86lidewell

    86lidewell Active Member

    Joined:
    Oct 10, 2020
    Messages:
    138
    Likes Received:
    163
    sp5it, thanks for that thread. It will give me a lot of meat to chew on.
     
    Handy Andy likes this.
  7. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

    Joined:
    Oct 23, 2017
    Messages:
    4,425
    Likes Received:
    6,833
    Some input tuning would probably help, along with increasing the negative feedback a little bit too. I have never tried this on a Texas Star, but it seems to really straighten out a comp style box.
     
    dave457 and 86lidewell like this.
  8. sp5it

    sp5it Master of puppets

    Joined:
    Jul 9, 2009
    Messages:
    1,912
    Likes Received:
    2,167
    Mission impossible. Look at picture I took. Red wire from ferrite transformer goes to power adjust pot. Only complete idiot could do it that way. This amp is garbage.
    Mike
     
  9. Handy Andy

    Handy Andy Do Your Research First, Then Decide...

    Joined:
    Apr 23, 2018
    Messages:
    4,939
    Likes Received:
    6,518
    For those whom are playing along at home...
    The WWDX Home Game version shows this...
    upload_2021-4-27_8-38-46.png

    Be careful of whom you send to - or receive mail from - you might get what you didn't wish for,

    But always wanted...

    Just not in a working state...
     
  10. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

    Joined:
    Oct 23, 2017
    Messages:
    4,425
    Likes Received:
    6,833
    Wow, I would never have thought to hook the transformer to the pot that way. My first thought would be to hook it up like a variable resistor and ground the other transformer wire.
     
    86lidewell likes this.
  11. Ranch55

    Ranch55 Sr. Member

    Joined:
    Jan 18, 2016
    Messages:
    620
    Likes Received:
    726
    Copper Electronics did not build it.
    Texas star warranty is easy and good to work with.
     
    NightThumper and Eldorado828 like this.
  12. 86lidewell

    86lidewell Active Member

    Joined:
    Oct 10, 2020
    Messages:
    138
    Likes Received:
    163
    they do the cw/11 meter mod
     
  13. 86lidewell

    86lidewell Active Member

    Joined:
    Oct 10, 2020
    Messages:
    138
    Likes Received:
    163
    some pictures of my 667v. Any help much appreciated.
     

    Attached Files:

    Shadetree Mechanic likes this.
  14. 86lidewell

    86lidewell Active Member

    Joined:
    Oct 10, 2020
    Messages:
    138
    Likes Received:
    163
    upload_2021-4-27_10-7-53.png had no impact on SWR
     
    Shadetree Mechanic likes this.
  15. sp5it

    sp5it Master of puppets

    Joined:
    Jul 9, 2009
    Messages:
    1,912
    Likes Received:
    2,167
    You have 2 options.
    1. Money back.
    2. Send this amp to someone who know how to rebuild it proper way. (Lose warranty if any)
    Mike
     

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!