Which SWR to believe?

[cockpitbob]

I have a fairly new FT-857D, a brand new MFJ-949E Versatuner with crossed-needle display and a 4 foot piece of RG8 between them. I finally figured out how to set the radio to display SWR during Tx. Naturally, the radio and tuner don't agree. On the shorter wavelengths the difference is substantial (1.5:1 vs. 3:1). In checking a 10M diople the 2 don't even think the lowest SWR happens at the same frequency. Either the antenna is perfect, or I need to cut it, depending on which meter I use. With a 50ohm dummy load they both say the SWR is perfect.

Any opinions on who's SWR meters suck more: Yaesu's internal or MFJ's?

 

[Zappa]

I don't trust either.

I check antenna match with a Bird 43 watt meter.
Rotate the slug 180 degrees counterclockwise and it shows true reflected power.

 

[brokenwire]

bird is the best

 

[cockpitbob]

No question that a Bird meter will tell the truth.
Once it got really late so I was sure 10M wouldn't go any where, I tried them at 100W into the dipole. The tuner's SWR meter gave the same readings and the radio's SWR readings changed to more closely agree with the tuner's. So, I guess I'll believe the tuner's meter until I upgrade. I suppose this makes sense as there probably isn't room inside that little radio to make a good all-band directional coupler.

 

[Realtor MA]

My 2 cents.....
The cross needle meters are nice and convenient but i think they're really hard to read accurately.
A bird meter will give you the real deal when it comes to SWR (if you do the math right) because it is measuring exactly what you want to see, forward and reflected power, with the same meter movement. A cross needle meter has 2 movements to deal with.
I have an mfj 259b which usually agrees with the bird calculations.
If you want to borrow either the mfj or the bird just let me know.

 

[radioman]

If you have tons of money get the Bird I agree their the best.

If your like the rest of us who can only afford the MFJ, I would go with the dedicated SWR meter reading. The SWR meter's only job is to measure SWR nothing else. The FT-857 has a meter that happens to read SWR along with about a 100 other things. I believe dedicated meters to have better reflected power sensors. I've used MFJ products all my ham career and I find them to be decent products for the money. I compare them to Lee reloading equipment. Cheap but good for what you pay. That's my 2 cents.

 

[cockpitbob]

Great advice all around. I am trying to not blow the bank and fill the house with stuff from another hobby. So, for now I'm going with "good enough". I think the tuner's crossed needles are good enough.

Radioman, thanks for confirming my suspicions that the radio has so much going on inside that it can't do many of them well, like measure SWR.

Realtor, thanks for the offer of the loaner equipment. I may take you up on it some day. Right now I've decided I need to focus on the annual December Death March: Work gets crazy with end of year shipments and performance reviews, plus a ton of relatives are coming for Christmas.

 

[Zappa]

I take it that we can all agree that the Bird is indeed The Word.

 

[Realtor MA]

Great advice all around. I am trying to not blow the bank and fill the house with stuff from another hobby. So, for now I'm going with "good enough". I think the tuner's crossed needles are good enough.

Radioman, thanks for confirming my suspicions that the radio has so much going on inside that it can't do many of them well, like measure SWR.

Realtor, thanks for the offer of the loaner equipment. I may take you up on it some day. Right now I've decided I need to focus on the annual December Death March: Work gets crazy with end of year shipments and performance reviews, plus a ton of relatives are coming for Christmas.

no worries. There's no expiration on the offer....