9.99 SWR

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M7KGH
 

Posts: 11
Joined: 19 Sep 2024, 12:09

9.99 SWR

Post by M7KGH »

My trusdx receives well but on CW into a dummy load is shows 0w and 9.99 SWR. On LSB/USB into a dummy load is shows 4-5w SWR varies obviously with voice.

Am I doing something wrong or did I screw something up in the build?

Or have I popped the finals already?
M7KGH
 

Posts: 11
Joined: 19 Sep 2024, 12:09

Re: 9.99 SWR

Post by M7KGH »

With the meter set to PWR-EFF I see 0.00w and 0.00% on all bands.
KE0QQQ
 

Posts: 65
Joined: 02 Aug 2022, 00:41

Re: 9.99 SWR

Post by KE0QQQ »

maybe not ? 9.99 SWR means all the power is reflecting back, like an open circuit?

is the dummy being dumb and is open? get the ohm meter out

use USB power till you figure it out

what is the antenna and connection to it?
M7KGH
 

Posts: 11
Joined: 19 Sep 2024, 12:09

Re: 9.99 SWR

Post by M7KGH »

It is an 80m dipole currently. Dummy load is measuring 50 ohms with MM.
KE0QQQ
 

Posts: 65
Joined: 02 Aug 2022, 00:41

Re: 9.99 SWR

Post by KE0QQQ »

I took my own advice and searched 9.99 SWR

.. https://forum.dl2man.de/search.php?st=0 ... R&start=25

There is an open circuit somewhere. The answers vary to the situation. Did you build it?

I know I had pin/solder issues with one radio I had. Never had a bad processor yet.
M7KGH
 

Posts: 11
Joined: 19 Sep 2024, 12:09

Re: 9.99 SWR

Post by M7KGH »

Ahh. Maybe all is not lost then. Looks like it could either be a bad connection or reversed winding on t1 & t2. I have ordered a second kit as well so will see how that one turns out. I wanted the different bands anyway and enjoyed building the first one so much.

I will get the MM out an take a look at T1 & T2
M7KGH
 

Posts: 11
Joined: 19 Sep 2024, 12:09

Re: 9.99 SWR

Post by M7KGH »

Image

So my T2 one of the windings goes the opposite way to the other and actually goes under the toroid. Not sure how I managed that ( I was tired). Despite the poor soldering they seem good connections. And as I said the receive seems good.
M7KGH
 

Posts: 11
Joined: 19 Sep 2024, 12:09

Re: 9.99 SWR

Post by M7KGH »

De-soldered, re-wound and re-soldered and now the SWR is 1. I am only seeing 2.5-3w with 65% effeciency though on all the bands
KE0QQQ
 

Posts: 65
Joined: 02 Aug 2022, 00:41

Re: 9.99 SWR

Post by KE0QQQ »

Cool beans, ya fixed it !

I am waiting for a decent watt meter myself to see what they can do. I get about the same reading from my little rigs when looking at the display

Psk reporter shows me going coast to coast from Minnesota with a little bit if Europe seeing me too doing FT8.

I have a End fed that does a nice short bounce on 40m and have had SSB qso's ranging out from 250 - to 400 miles. If I take the time and zero out the feq setting, the reports back are quite good.

Fun, fun !
M7KGH
 

Posts: 11
Joined: 19 Sep 2024, 12:09

Re: 9.99 SWR

Post by M7KGH »

I appreciate the help. I'm waiting on my nano vna from AliExpress so I can try and properly tune it. I also need to get a decent antenna set up. I've heard Russia, Italy and Germany on mine (I'm in England (or Slavic speaking countries). I have made no contacts though (not tried since fixing T2).

I have a Yaesu FT817 here as well and interestingly they seem fairly closely matched. The Yaesu is slightly more sensitive but also picks up a lot more noise. Sometimes weak signals are more audible on the trusdx other times the Yaesu. I actually find the trusdx easier to use as well.

So you think 65% is useable at 3-3.5w?
KE0QQQ
 

Posts: 65
Joined: 02 Aug 2022, 00:41

Re: 9.99 SWR

Post by KE0QQQ »

Hello !

Here is who heard me the other day on FT8. I was using a 66 foot EFHW and the little transformer kit from K6ARK.com in my back yard. I had it up 25 feet and sloped at a 30° angle for the rest of it, tying it off to the fence

40m is nearly NVIS. My house is a 2 story with steel siding. I think it plays with the pattern as well, seemingly helping my eastward pop on 40m, where all the people are in the US. The house is actually in the way for an easterly path. Go figure. Alot of these responses are way down on signal. -10 to -20 on FT8
yellow is 20m, blue is 40m
3wFT8.png
3wFT8.png (179.05 KiB) Viewed 1066 times
blue.jpg
blue.jpg (86.1 KiB) Viewed 1066 times
DH7CS
 

Posts: 8
Joined: 28 Jul 2024, 11:17

Re: 9.99 SWR

Post by DH7CS »

Dear OM,

after longer periode without any issues i need to ask for help in this forum :D

facing the same problem with 11w @ swr 9.99

assembled kit Lo bands.
worked well.
popped my BS170 twice
re-installed new onces
worked so far well

last job was a FT8-session with a tablett /portable

during a short check at home (20m-dipol under roof, my FT710 & G90 like it) - same as on first thread - unbelieveble high power arround 11w and SWR 9.99


most of the times i read about this it was wrong installed spools/transformers.

Can´t see any cold welding point - as there´s no mechanic impact on the platine inside.
maybe only the antenna and mic/speaker jacks - antenna looks/feels "solid".


i´m sorry, but i´m not the eletronic-crack - at least i was able to re-install my BS170 three times :-)

maybe i´ve overlooked something and/or you have any small hint for me?

merci/73
chris
DH7RK
KE0QQQ
 

Posts: 65
Joined: 02 Aug 2022, 00:41

Re: 9.99 SWR

Post by KE0QQQ »

OK,, just small hints :)

Searching 9.99 SWR , Go back to the beginning of time here. Like Jan 2022. It is noted that the logic of the radio can be tricked to read a high output when the SWR is crazy.

Then I learned if you do have one HOT BS170, clip it off. You may have simply a bad BS170. OR not matched to its brothers very well.

Since the Finals are in parallel it seems you can ride on 2 or maybe one of them. I have not tried this yet.

One thing I did was throw out that SMA to BNC adapter and use a coax lead , SMA to 239. my picture above does not show this very clearly. To me, that adapter seemed like it was always loose

There I learned some SMA have a button for the center, others have a PIN. You need the PIN

Winter building season is here. I did get a holiday sale logic board and need to get the high powered eye glasses out and remember which end of the iron is hot.
DH7CS
 

Posts: 8
Joined: 28 Jul 2024, 11:17

Re: 9.99 SWR

Post by DH7CS »

Morning!!
Did replace the BS170 - back on track :-)

But i also learned the internal Power-meter seems to be not accurate?

Internal 2.5-3w output in ssb
External MFJ Meter says 5-5.5w

Anyway, it works

Need to build a new box for the TRX as i melted several times the plastic :-)

73 de
DH7CS
Chris
KE0QQQ
 

Posts: 65
Joined: 02 Aug 2022, 00:41

Re: 9.99 SWR

Post by KE0QQQ »

Back on the air ! Sweet

Once I got my BS170 version going, my finals just barely got warm when pressing it with 3 cells and FT8 all day, My guess is those first finals were not happy together.

I wonder what we can adjust to align the perceived output to the actual output.

My SWR seems close between using my MFJ box to the read out, with the radio always showing a lower value than my MFJ
PP2PB
 

Posts: 10
Joined: 31 Oct 2024, 13:04

Re: 9.99 SWR

Post by PP2PB »

Regarding the power readings, all power meters, unless lab calibrated, usually have up to 10% error margin, on top of that measuring qrp levels of power when the meter is rated at 100W or more may add to the error.
The most accurate way would be measuring peak to peak voltage (with an oscilloscope) on a dummy load and convert to Watts. Even cheaper ones should do ok.
Manuel has one or more videos on how to do it.

My oscilloscope readings were extremely close to the displayed power on the (tr)uSDX
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