Stefan...thank you very much for producing this excellent video. I admire your electrical engineering skill and knowledge. I own a MFJ-993B that fortunately seems to operate with no issues thus far...however after watching your video, and after seeing the design flaws and somewhat shoddy construction...perhaps I've just been very lucky! Compare the design and construction of this HF auto-tuner versus something like the Palstar HF-AUTO antenna tuner. Yes...the Palstar is significantly more expensive, however you get what you pay for. One looks like it's built to withstand war and the other...well...you get my point. Again, thank you & 73's!
Years ago I found a problem with a MFJ tuner was the SO-239 connectors as the "fingers" inside the connector that wrap around the PL-259 center conductor pin were a bit loose. This was a defect of the connector manufacturer. Don't know what they're using today but you might check those just for grins! Thanks for sharing Stefan! 73 - Dino KLØS
In order for the tuner to auto-tune you have to have the appropriate cable to connect the different radios to it. I'm going to assume you have the appropriate cable for this radio you are testing.
Acc. to the manual, this tuner operates automatically without the remote port. The tuner measures the frequency and stores the related settings. Te remote port is used to control the tuner remote if wanted - but not necessarily! The owner uses an old TRX without serial connection.
Stefan...thank you very much for producing this excellent video. I admire your electrical engineering skill and knowledge. I own a MFJ-993B that fortunately seems to operate with no issues thus far...however after watching your video, and after seeing the design flaws and somewhat shoddy construction...perhaps I've just been very lucky! Compare the design and construction of this HF auto-tuner versus something like the Palstar HF-AUTO antenna tuner. Yes...the Palstar is significantly more expensive, however you get what you pay for. One looks like it's built to withstand war and the other...well...you get my point. Again, thank you & 73's!
Again an interesting repair video Stefan, many thanks, 73 from Toni, PA0YRA !!
Many thanks for the info, good explanation for us not so clever Hams .
don't hide your light under a bushel...hi
Years ago I found a problem with a MFJ tuner was the SO-239 connectors as the "fingers" inside the connector that wrap around the PL-259 center conductor pin were a bit loose. This was a defect of the connector manufacturer. Don't know what they're using today but you might check those just for grins! Thanks for sharing Stefan! 73 - Dino KLØS
Yes Dino, but i checked the total continuity with the external measurement of power flow through it; the PL wasn´t the problem here.
Looks like it may be a "rollback" issue with the radio vs SWR. ICOM 7200's act this way.
excellent ...thanks
Thanks Stefan. MFJ offers cheap stuff for hams. Okay if your budget is limited.
Hi Joe, Yes, but i think the circuit and electronic concept is OK, only the mechanical quality offers space for improvements.
Well done again!
In order for the tuner to auto-tune you have to have the appropriate cable to connect the different radios to it. I'm going to assume you have the appropriate cable for this radio you are testing.
Acc. to the manual, this tuner operates automatically without the remote port. The tuner measures the frequency and stores the related settings. Te remote port is used to control the tuner remote if wanted - but not necessarily!
The owner uses an old TRX without serial connection.
Hi good afternoon, :This is KC2DPY. I have the same tuner but when my radio has the preamp on its do not tune,any suggestions.
Sorry, no idea what the preamp has to do with the tuner. Maybe a problem with the antenna- and preamp relays?
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