667v high swr decreases with modulation

[86lidewell]

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.

 

[sp5it]

Parasitic oscillation. Send it back. I had similar problem with 667.
Mike

 

[86lidewell]

copper electronics

 

[86lidewell]

https://www.worldwidedx.com/threads/new-667v-issues.258647/

 

[sp5it]

Yes, this amp. Went back to the store.

 

[86lidewell]

sp5it, thanks for that thread. It will give me a lot of meat to chew on.

 

[Shadetree Mechanic]

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.

 

[sp5it]

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

 

[Handy Andy]

For those whom are playing along at home...
The WWDX Home Game version shows this...
​

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...

 

[Shadetree Mechanic]

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.

 

[Ranch55]

copper electronics

Copper Electronics did not build it.
Texas star warranty is easy and good to work with.

 

[86lidewell]

they do the cw/11 meter mod

 

[86lidewell]

some pictures of my 667v. Any help much appreciated.

 

[86lidewell]

had no impact on SWR

 

[sp5it]

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