Hi,

The real reason that auto tuners may not work in all situations as well as manual ones is that they just don't have the same range and variability in capacitance and inductance values. Where a manual tuner has a continuously variable set of caps, and perhaps a roller inductor, though even if it's tapped…anyway…most auto tuners have fixed value components that get switched in and out with relays in order to make up L andC values. While these are pretty darn close, you can only fit so many in a given space, and besides, what about those spaces between values? The other issue, of course, is that the tuner is further from the antenna. Ideally, and usually not possible, a tuner would be right at the antenna feed point. In other words, there's no real reason a manual tuner *has* to be more efficient, but of course, there are always tradeoffs. Frankly, there are some auto tuners, such as the ones in the Elecraft gear, that are quite good and will match the proverbial wet noodle. But even so, I bet there are some things that won't match with anything less than a good roller inductor tuner. But at that point, how much are you really radiating anyway? Any tuner's a compromise. Whether you lose your power right at the transmitter, or lose it in heat in an outboard tuner, you're probably still going to see some loss. Heck, you'll see *some* loss in any multi band, and thus compromise, antenna. So I guess it boils down to--if it works, use it. Being aware of the compromises you're willing to live with. 
--
Buddy Brannan, KB5ELV - Erie, PA
Phone: (814) 860-3194 or 888-75-BUDDY



On Aug 15, 2012, at 7:04 PM, Tom Behler <[log in to unmask]> wrote:

>    Bob:
> 
> Well, whenever I tune for low SWR with the 480, I turn the auto-tuner off.
> 
> I assume that, when it is off, it is in completely bypass mode.
> 
> And, yes, I agree;  I'll prefer a manual tuner over an auto-tuner any day, 
> in terms of power loss considerations.  I actually have a little MFJ 901B 
> manual tuner that I should take out to the RV just to see if it is more 
> efficient and less lossy than the TS480's internal tuner.
> 
> Tom Behler: KB8TYJ
> 
> ----- Original Message ----- 
> From: "Bob, K8LR" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, August 15, 2012 7:46 AM
> Subject: Re: Tuning aids, noise bridges, etc.
> 
> 
>> Tom,
>> 
>> since you have an internal tuner in your TS480, it will either tune the
>> antenna or you'll get a SWR cw error message.  Just remember that an
>> internal tuner is not very efficient, it usually sucks out between 10%
>> and15% of the output power.  As Buddy mentioned, its not a good idea to 
>> hook
>> up a watt or SWR meter after an internal tuner as your readings will be 
>> way
>> off.
>> 
>> Bob, K8LR, [log in to unmask]
>> 
>> ----- Original Message ----- 
>> From: "Buddy Brannan" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Wednesday, August 15, 2012 7:04 AM
>> Subject: Re: Tuning aids, noise bridges, etc.
>> 
>> 
>>   Tom,
>> 
>> You do realize that the TW1 won't actually tell you anything about what =
>> your internal tuner is doing, right?
>> 
>> I mean, the meter goes before the tuner, which is impossible if the =
>> tuner is internal. So, yeah, you'll get your power out racing, but you =
>> won't get an active WR reading, at least not as far as your rig is =
>> concerned. It's going to see whatever the internal tuner matches to, but =
>> the TW1 won't, since it's necessarily in line after the tuner, not =
>> before.=20
>> --
>> Buddy Brannan, KB5ELV - Erie, PA
>> Phone: (814) 860-3194 or 888-75-BUDDY
>> 
>> 
>> 
>> On Aug 15, 2012, at 6:59 AM, Tom Behler <[log in to unmask]> wrote:
>> 
>>> Hi, all.
>>> =20
>>> I have debated about posting this right now, especially in light of =
>> all of=20
>>> the traffic regarding Trippy's ccurrent saga, since the question I'm =
>> going=20
>>> to ask may involve posting some repetitive info that already is =
>> included in=20
>>> the discussion threads.  However, I'm hoping that any responses will =
>> pull=20
>>> together some knowledge that will help both me and others.  If =
>> responding to=20
>>> this quiry does involve too much repetition, please feel free to reply =
>> off=20
>>> list.
>>> =20
>>> As many of you know, I'm struggling with my HF antenna situation out =
>> at the=20
>>> RV.  In fact,  the ham radio withdrawals are getting worse with each =
>> passing=20
>>> week, and I may have to take Howard's Zannex advice soon (grin).
>>> =20
>>> I'm actually now very close to trying to put up my extra 102-foot G5RV =
>> out=20
>>> at the camp site, at least temporarily, just to see how it does.  I'll =
>> have=20
>>> to get clearance from camp ground management, but I hope the fact that =
>> we=20
>>> have a seasonal pass will help.
>>> =20
>>> When I do any antenna work out at the RV, I always take the 1 and only =
>> TW1=20
>>> that I have, so as to be sure to tune for lowest SWR.  It involves =
>> tearing=20
>>> my home station apart a bit, but is well worth the sacrifice, since I =
>> don't=20
>>> want to become victim to what Trippy apparently just experienced.  I =
>> realize=20
>>> that the auto-tuner in my  TS480SAT  should keep me out of trouble, =
>> but I=20
>>> just want to be doubly sure.
>>> =20
>>> Anyway, I am in the market for some sort of a tuning aid to use out at =
>> the=20
>>> RV.  I'd love to get my hands on a used TW1, and will keep a lookout =
>> for 1.
>>> =20
>>> In the event I can't find one, mention of noise bridges has been made =
>> here=20
>>> on a number of ocasions.  Which noise bridge have you guys found to =
>> work the=20
>>> best, and can you give me price and other info?
>>> =20
>>> I could also call Handihams to see if they have any of their old =
>> tuning aids=20
>>> left, but I believe those are no longer available on a consistent =
>> basis.
>>> =20
>>> Thanks as always and 73 from Tom Behler: KB8TYJ
>>