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Re: Tuner? Well Sure!


 

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Well make a simple DC calculation for a 2 ohm antenna at 100 watts and see what you get¡­ ?I get 7 amps plus.? I build for worst case so it doesn¡¯t break and come back.? The worst think that can happen is to under-design, sell a product, have people use it and be disappointed because it fails when they need it to work.? I¡¯m really tired of products that are built that way¡­ and there are a lot of them.? I spend most of my weekends fixing other people¡¯s bad design with products around my house and had enough of it.? Pool stuff appears to be the weakest.? Cars are not far behind.? Seems like there is always a battery to replace every weekend too.? Sorry¡­ \\endrant.

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Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

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Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

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Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

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email:? bill@...

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From: [email protected] [mailto:[email protected]] On Behalf Of Diver Martin
Sent: Sunday, December 31, 2017 3:08 PM
To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

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Bill, 7 Amps?? Can't say I've used a relay that beefy.? I'm using IM43 latching relays in my tuner.? They're about a buck 50 a pop in volume.? I tune at 1W, transmit at 50W.?

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I am still pondering making my motherboard add-on.? But I"m sure the way I roll it'll be pricier than $40 fully assembled.? Significantly, but then I'd be replacing the raduino completely too, adding DDS spots, and other stuff.

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On Sun, Dec 31, 2017 at 12:44 PM, K9HZ <bill@...> wrote:

Not sure I fully understand this WINLKNK and ALE stuff yet, but in ¡°memory mode¡± where the Raduino passes the Tunerino (huh, new word coined here! ¡°Tunerino¡±) the new operating frequency, the tuner can use stored past operating parameters to start from¡­ and if you continue to use the same antenna¡­ it probably will not engage the tuning routines (depending on the match on transmit¡­for receive it won¡¯t make much of a difference).? In this case, the tuner can react faster than the radio.? If there is transmission and mismatch from the last transmission on that frequency, it starts from current position and may just need to slightly adjust¡­just a step or two.? I would recommend this mode for your fixed antennas at your house¡­ but not for something you take camping, on field day, or where the antenna changes frequently.

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<< Both systems however spend MOST of their time SCANNING and hence they are changing? bands but there is no transmitted energy so the automated tuner has no idea what is going on.....>>? Unless you pass frequency data¡­ then it can operate in memory mode and be extremely

efficient.

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<< it would be brighter for both systems if some means of RFI-impervious connection between the transceiver and the tuner allowed it to know when receive frequency was changing>>? Yep¡­ that¡¯s the plan, man¡­ smart tuners all work this way today.

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<<I'm suspecting that there are far fewer people who want the lowest current drain for battery usage....and far more who would appreciate lower cost and are willing to provide power for relays where needed.....but this is just a guess.? ?I haven't watched to see what kind of relays are used in the MFJ and LDG products but their gear is commercially successfulll.....just pricey.?? ?Relays must be cheaper than variable capacitors and servo motors!>>? Well this is my current dilemma.? I can buy good quality relays that will work for this project for $0.39 each (need to be a minimum of 7 amps).? Using 18 of them, I can keep the cost of the kit in the $30-$40 range as originally discussed.? Latching relays of the same specifications are in the $4 each range¡­ making the total cost jump up an ADDITIONAL $65 !!!?

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Now my question to the group is this¡­? would you rather have a very functional tuner but draws additional constant current¡­. Or a tuner that draws very little current once tuned but is $65 more expensive?? I don¡¯t do too much battery operation myself¡­ but I am sensitive to those who do.? If every relay were engaged (not likely) it would draw 1.2 amps total (60ma each).

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Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

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Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

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Like us on Facebook!

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email:? bill@...

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From: [email protected] [mailto:[email protected]] On Behalf Of Gordon Gibby
Sent: Sunday, December 31, 2017 1:35 PM
To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

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Hi,??

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WINLINK and ALE are two different animals.

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Both scan frequencies on multiple bands constantly.? ?WINLINK scan each frequency for 3-6 seconds depending on which modes are to be? detected.? ?ALE scans each frequency for 1, 1/2 or 1/5 second depending on operator preference (I think).? ?1 second is OK, 1/2 second is considered good and 1/5 second speed is considered excellent.

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For both systems, the "crude" solution is simply not to tune until there is actually transmission occurring.? ?

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I *think* for ALE it is a more constant power, just moving between 8 tones (but not sure about that yet)

For WININK it can be a mess, with multiple different protocols being transmitted.? ?I've watched LDG tuners iterate throughout the entire 10 second call and still not be matched because they keep being thrown for a loop by all the changing amplitudes etc.

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Once a setting is memorized, tuners seem to do MUCH better for both.

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Both systems however spend MOST of their time SCANNING and hence they are changing? bands but there is no transmitted energy so the automated tuner has no idea what is going on.....

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This leads to less-than-optimal energy reaching the receiver at times.....Winlink sometimes implments a venerable soution of just tuning for the HIGHEST band and leaving it there while they do receiver scanning until next needed.

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it would be brighter for both systems if some means of RFI-impervious connection between the transceiver and the tuner allowed it to know when receive frequency was changing.? ?However, this might lead to a HUGE number of relay clicks particularly for ALE at fast scan? rates, and this might be prohibitive for long term reliability.? ?WINLINK's slow scan rate might make it workable.

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FEW PEOPLE ACTUALLY NEED THAT RECEIVE ADJUSTMENT CAPABILITY however --- so it may not be commercially viable.? ?There are maybe 50 server stations for winlink in the US and I don't know how many ALE users are actually ever active.

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OK....that may be far more than you wanted to know, but understanding the user-issues always seemed important to me in product development.

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I'm suspecting that there are far fewer people who want the lowest current drain for battery usage....and far more who would appreciate lower cost and are willing to provide power for relays where needed.....but this is just a guess.? ?I haven't watched to see what kind of relays are used in the MFJ and LDG products but their gear is commercially successfulll.....just pricey.?? ?Relays must be chaper than variable capacitors and servo motors!

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Gordon

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Martin Held - AE7EU


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