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  1. BITX20
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Tuner? Well Sure!

 

I'm intersted in a kit as well (ZL2TUD)
I have been using OMRON? G2RL-1-E-CF relays for filter /antenna selection they are good to over 1kW CW and are relatively cheap differnt coil voltages are available
This is backed up by W6PQL who has done lots of testing and uses them up to 70cm.
The inards of these relays is very close to the relay corners and an inadvertant touch with the soldering iron will render the relay useless.
No relay will handle huge RF currents while switching so tuning has to be done at reduced power
John Faivre
 

I¡¯m planning to build a version of the K3NG auto tuner as well. I am looking at using a Sainsmart 16 relay module (Amazon $14.99) for the L&C and a 2 relay version for the hi/lo and antenna switch. N9KR used these modules. (Search YouTube for N9KR). Also going unbalanced. Great info on the SWR detectors. I plan to build in a noise bridge as well for no transmit tuning.?
--
John Faivre?WA9SGD
 

What ever happened to this project?

Roy
WA0YMH
 

Put me on the list for an ATU kit.? You're going to need a lot of them in your first PCB order!

Bert N8NN
 

Noted.
Maybe a separate one apart from the antenna requirements.
Thanks and regards
Lawrence

On Sun, Dec 31, 2017 at 2:34 AM, K9HZ <bill@...> wrote:

Well 160 will easily be covered but 630M is a much larger task.? The efficiency of a wire that is less than 0.2 wave lengths (close to 400 feet!) on that frequency with a tuner is extremely low (most of the power is radiated by the tuner and feedline).? The best thing to do is put up the longest wire you can (500 feet min) then the tuner might have a chance.

?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

Like us on Facebook!

?

?

email:? bill@...

?

From: [email protected] [mailto:[email protected]] On Behalf Of Lawrence Galea
Sent: Saturday, December 30, 2017 9:35 AM
To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

?

You can count me in.

A 160M addition would encourage more operators to try this band which is also my favourite.

?

While at it, would it be possible to include 630M??

Although I am not sure that the ¦Ìbitx could be persuaded to tx down there with an additional LPF/BPF it would make more operators try the band.

?

Couple of quotes from emails.

?

"I actually changed the lowest frequency to 100000L. I want to see if 2200M will work, also. My antenna will never tune to these frequencies, but I want to see if I can hear anything....?KG5PRT"

"Group,?With a filter front end and a small preamp I was able to hear a NDB beacon at 209.00KHz with my Ubitx. the readout read something like 2.09.059...this was a stock UBitx...Hope this helps! Mike WA3O "

So it may be feasible.

?

Thanks and regards

Lawrence

?

?
 

Hi Gordon,
Fantastic idea.
I would be interested
73's
Mans. 9H1GB

On 29 December 2017 at 16:05, K9HZ <bill@...> wrote:

So after finishing up most of my projects a few days ago¡­ I really needed something to do¡­ so I put on the drawing board¡­ a 100w automatic tuner that can work with the uBITx (intended to go inside the same case actually) that provides power, SWR, band memory for same antennas, low power tune, bypass, etc. all in a kit form for about $30.? I¡¯m prototyping the think now and will work on the tuning/communications code (to integrate into the Raduino) shortly.? I¡¯ve contacted a few of you off-channel to work out some protocol/communication issues¡­? but Stay tuned (double play on words there)! ???

?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

Like us on Facebook!

?

?

email:? bill@...

?

From: [email protected] [mailto:[email protected]] On Behalf Of Gordon Gibby
Sent: Friday, December 29, 2017 8:21 AM
To: [email protected]
Subject: Re: [BITX20] ALE, WINLINK and uBitX

?

Good pickups!

?

So the ALE (automatic link establishment) crowd, much like the WINLINK crowd, tend to use LOTS of bands....and thus they find ways to make their antenna systems work on mulltiple bands.? ?Here are some of the most popular ways:

?

1.? ?Fan Dipoles (time honored technique of tying multiple dipoles together at the CENTER, and the energy tends to go to the correct one, since all the others present much higher impedances.? ?The wires "fan" out with usually wooden spreaders at the? end and some string involved to keep them somewhat separate.? ?Been there done that many times, my college ham club has a 3-band unit up on the top of an 11 story building rightnow that I built for them.? ?Build for yourself, dirt cheap.?

?

2.? Auto-tuners? --- everyone makes these now and many can tune as soon as they see RF, or even return to previous settings that were memorized.? ?LDG,? and others.? ?Low power versions for $100? ?End fed wire to balanced line fed dipoles---they work with lots of different kinds of wire.?

?

3.? Inherently multiband antennas:? ?example, full wavelength loops.? ?Build for yourself.? ?

?

4.? Carefully tuned end-fed transformer-fed antennas --- there are now several of these on the market and they give an acceptable SWR on mulltiple harmonically related bands.? ?Tend to be close to $100

?

5.? (the one I dislike)? resistively terminated folded dipoles --- these use a resistor to make up for what a folded dipole can't create and give an SWR that is "acceptable" literally across EVERY FREQUENCY in a decade of frequencies.? ?3-30 MHz.? ?The tradeoff is loss, as much as 10 db at times.? And they generally are pricey.

?

6.? There are some multi-band vertical antennas on the market that are basically vertical fan dipoles, but scrunched up in a nice package.? ?An elderly ham in my city has one, 32 feet tall....a gang of us put it up and doggone it does from from 40 meters all the way through 6 meters

?

?

And there are probably many more....

?

Gordon

From: [email protected] <[email protected]> on behalf of Arvo KD9HLC via Groups.Io <arvopl@...>
Sent: Friday, December 29, 2017 9:12 AM
To: [email protected]
Subject: Re: [BITX20] ALE, WINLINK and uBitX

?

An automatic tuner protects the rig during TX.? If the SWR is bad during TX, some of the signal coming out of the transmitter is reflected by the antenna back into the radio where it can cause damage.

That said, RX is optimized by a properly tuned antenna, but some good amount of signal still makes into the radio when receiving, even when the antenna is not perfect.

So I assume Doc G? is scanning for radio traffic, and then when he finds some if he wants to transmit he does something about his SWR for that frequency.


 

You might consider making the relays a separate board from the controller. That what it could be built with different relays or for different power levels. A bit more expensive for an additional board but I could see the basic controller used for several different applications.? Just a thought.
John Kemker
 

Not only willing to be a beta tester,? willing to assemble.
--

73 de W5NNH
 

most is here

glenn
vk3pe
Diver Martin
 

Glenn,

Nice PCB layouts!? Digging your projects as pictured on QRZ...? Do you have schematics/etc posted anywhere?? Love seeing other's homebrew stuff.

For now linear SWR-only tuning works, but eventually I should get to phase/magnitude detection.? What's interesting to me when I went and looked at the KX3 is that it doesn't actually have a phase detector that I can tell.??

Bill, now you've gotten me interested in Sabin's book, as if I didn't have enough reading material to begin with :)? I doubt I'll make an update to the amplifier design at this stage since I've gotten it working, but never know.

On Sun, Dec 31, 2017 at 3:50 PM, Glenn <glennp@...> wrote:
My Control board takes a plug IN NANO baord and caters for a few different display type from parallel LCD's to I2C devices. It has provision for LED's to indicate which relay combination of L&C is slectedas it tunes.? Overkill really....... PCB could be made much smaller of course.




--
Martin Held - AE7EU

-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
 

Bill-interested in a kit and could do some building also.
Andy KM4TRT
 

My Control board takes a plug IN NANO baord and caters for a few different display type from parallel LCD's to I2C devices. It has provision for LED's to indicate which relay combination of L&C is slectedas it tunes.? Overkill really....... PCB could be made much smaller of course.

Control_PCB_TOP.JPG

 

Hi Bill, thanks for the warm welcome.

I used the AD8307's because they work much better at lower power levels. And off ebay they are extremely cheap.

The project already has two relays for switching the caps to either end of the inductors. You can see them on the PCB, which by the way is 100 x 100mm which is the sweet spot for getting Chinese PCB's made these days.

I like the concept of using Phase and Magnitude from something like an AD8302, but I am a total noob re programming Arduino so elected to go down the path that K3NG has gone.
Glenn
vk3pe
 

¿ªÔÆÌåÓý

Glenn.? Welcome aboard and hope to work with you more¡­

?

Yes I see you have been working at this project for a while now.? You have developed some very nice boards.? I¡¯ve used the AD8307 on a lot of projects too and they are wonderful for power resolution since they are native logarithmic/ decade devices, but they are not necessary for an inexpensive a tuner.? It also tells me that you are using a straight linear hunting algorithm to find the lowest SWR calculated from forward and reverse power. ?I did that with the first tuner I built, but moved to using Phase and Magnitude measurements instead¡­ as they give you more information (add L, add C, etc.)¡­ and then just calculate power using math routines now available in the processor libraries.? If you make a revision to those boards, I strongly suggest you add two additional relays to put the capacitor network on either side of the inductor.? That completes the transform space needed to be covered for both hi-Z and low-Z antennas.? Again all subjects covered in Sabin¡¯s book¡­

?

You are very right.? The relays make and break the project.? Been there, done that and suffered in between.?

?

I do like the caps you use¡­? I¡¯ll see if I can source those here¡­ don¡¯t see why not, but they seem to be high current density devices¡­ needed for RF designs like this.

?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

Like us on Facebook!

?

?

email:? bill@...

?

From: [email protected] [mailto:[email protected]] On Behalf Of Glenn
Sent: Sunday, December 31, 2017 4:33 PM
To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

?

My 1st post. Have a look at the K3NG ATU (Google K3NG TUNER). While he designed it as a balanced tuner, I have built an unbalanced version for around 20W or so. Using standard footprint 'cheap' relays. Actually the relays are the bugbear of an ATU, finding the right type and rating and low cost, since in this example there are 18 relays. From what I can see, latched relays are very expensive especially when you need 18. The trade-off is current draw, as per some posts here.

I used AD8307 Log detector chips in the SWR section. Caps used were 3kV rated 1812 sized smd although available in VK, might be harder to find in USA.

K3NG uses an Arduino NANO and a simple 2 line LCD module.? To keep size down, one of the 0.96" OLED displays might be a candidate.

glenn
vk3pe

Diver Martin
 

K3NG provides a good starting point. But I found a few flaws in the algorithm that he uses, at least so I think.? Here is the comment I put in my code for my ATU, and my thoughts.? Warning:? Long read ahead.? You might wish to just mark this one as read unless you're into the nitty gritty of ATU code revD.

/* Tuning Algorithm Description
?*?
?* This tuning algorithm is a refinement of the algorithm used by k3ng and others.??
?*?
?* Editors note:? **This is based on my assumptions and understanding of the algorithms.? They could be totally wrong!
?*?
?* This algorithm allows for all possible L/C/CX combinations to be potential candidates.? For reference, the k3ng algorithm does a?
?* matrix scan, wherein (assuming 8 inductors, and 8 capacitors) it does a scan of all individual C values with all individual L?
?* values.? That is, if C and L are values from 0 to 255, a value of * 1 (0001) is say 0.0625uH, a value of 2 (0010) is 0.125uH, a?
?* value of 4 (0100) is 0.25uH, and so on.? Capacitor values start at 10pF would be 1=10pF, 2=20pF, 4=40pF, etc such that if you?
?* set C=180, that should be a value of 128 + 32 + 16 + 4 or 1800pF.
?*?
?* The K3NG algorithm** tries (almost) all values of L and C where only one L/C is selected, that is first C is set to 1 (10pF),
?* and then L is set to 0.0625, 0.125, 0.25, 0.5, 1, 2, 4, and 8uH.? (L = 1, 2, 4, 8, 16, 32, 64, and 128).? C is then set 2 (20pF),?
?* and this is repeated.? C is then set to 4 (40pF) and all 8 inductors are tried.? At this point, you now have an 8x8 grid / matrix
?* of SWR measurements.? Whichever combination yielded the best (lowest) SWR reading, you focus on that point and then scan from +/- 8
?* or 16 values depending on the algorithm for a 'best' match.? (You repeat this 8x8 array measurement, as you do it once for the
?* capacitor on the High-z side, and once on the low-z side, for 8x8x2=128 total measurements).? For example, say the first stage
?* yielded a result of CX=0, L=16 and C=32 as the lowest SWR of 2.5:1.? You would then scan from L=8 to L=24 and C=16 to C=48 in a
?* similar grid fashion to arrive at finding L=22, C=36 as the best combination yielding a 1.5:1 SWR.? Great, all tuned up!
?* Except there's a flaw in this algorithm, a significant one at that.? Lets say the first round yields best match at L=128 (for
?* the purposes of this exercise, lets assume capacitance is irrelevant).? You then scan from from L(round1) +/- 16 so you try all
?* values of L between L=112 to 144.? But you don't find a match...? why not?? Because the best match was at L=100.? So why did the
?* algorithm not try L=64?? Lets see.? L=64 +/- 16 yields L from 48 to 80.? L=100 is literally an unobtainable value.
?*?
?* So to refine on the algorithms used above, my algorithm is a 3-stage algorith, but instead of a non-linear power of 2 matrix,?
?* I use linear values.? Because this tuner has 7 inductors, 8 capacitors, and 1 relay for switching CX (high-z/low-z), I use a?
?* 7-6-6 and 6-5-5 matrix.? That is, I scan 7 values of C from 0 to 255, and 6 values of L from 0 to 128 in stage 1.? So the first
?* scan matrix is 7x6 values.? You'll note that when the algorithm is first triggered (look above about 115 lines up) that?
?* L=11 and C=18 are the initial values, and that each round, L is incremented by 22, and C incremented by 36.? This means we try
?* inductance values L=11, 33, 55, 77, 99, and 121.? C values tried are 18, 54, 90, 126, 192, 198 and 234.? The downside to doing?
?* a linear scan is that it will flip a lot more relays.? Boo hoo!? From there, the best L/C value is picked + highz/lowz, and?
?* then proceeds to stage 2, incrementing L/C by 4 and 6.? So if L=11 and C=18 are picked, then L=0+(4/2)=2, L=6, L=10, L=14, and?
?* L=18 (5 values)are tested to cover the L=0 to L=22 range (remember, round one tested L=11 and L=33, so we want to ensure we can?
?* cover to the midpoint between 11 and 33, which is 22).? The capacitor does the same, except it'll go from C=3, C=9, C=15, C=21,?
?* C=27, and C=33 to cover C=0 to 36 (round 1 was C=18 and C=54).
?*?
?* The final stage is naturally a simple by-1 increment.? So if L=2, C=3 were the best values, it'll do L=0, L=1, L=2, L=3, and L=4
?* as well as C=0, C=1, C=2, etc (I think you get the idea by now).
?*?
?* You'll notice an odd -1 in there... that's because the Actual L/C values are 0-127 and 0-255, whereas this algorithm really ends?
?* up covering 1-256 and 1-128, so I subtract one... at least, that's my story and I'm sticking too it.? Either way, we can show
?* coverage as well by simple multiplication:? 6*5*5 = 150 (and we just need 0-128), so we're almost over-covered.? 7*6*6 = 252,?
?* which is just a few shy, so there might be a few values (a grand total of 3) where we might not reach the best SWR, but we'll?
?* get pretty close.??
?*?
?* This algorithm could easily be extended to more rounds for faster search times.? This is an exercise for later, because I fear
?* one little issue:? THe SWR is not always linear with a clearly distinct 'null'.? For example of a 1-dimensional tuner (ignoring
?* capacitance), if during round L=33 gave SWR=3.0 and L=121 gave SWR=3.1, you'd pick L=33.? But what if L=33 was near a 'local'?
?* null in SWR where it never got better than 2.5:1, whereas the 'best' match was at L=140 with SWR 1:1.? You'd never find it. Now,
?* Granted, this can happen now... but the finer your first stage, the less likely, and this is an important consideration for?
?* going to multiple rounds.? For example, lets go extreme with 8 rounds, and only 2 values each.? Test L=32 and L=96 (L=0 to 128).??
?* You can see how a non-linearity in the SWR curve vs inductance might pick the wrong L value.? The one advantage to an 8-round
?* tuning system is (Lets say we have L=0-255 and C=0-255 for simplicity).
?* 1 round, extreme, you'd need 256*256 measurements = 65535 to cover all possible measurements
?* 2 rounds, you need 16*16 + 16*16 = 512 total measurements.
?* 3 rounds (as above), 7*6 + 6*5 + 6*5 = 102 total measurements
?* 4 rounds (4*4*4*4=256, works out nicely), you need 4x (4x4) matricies, or 4*16 = 64 total measurements
?* 6 rounds (256^ (1/6) = 2.51, so we'll have to go (3*3*3*3*2*2) or 39 total measurements
?* 8 rounds (2 each) = 4*8 = 32 total measurements
?*?
?* So as you can see, there is an advantage to doing more rounds, but your tradeoff is you're more vulnerable to local nulls in
?* the SWR of your antenna.
?*?
?*/

On Sun, Dec 31, 2017 at 2:32 PM, Glenn <glennp@...> wrote:
My 1st post. Have a look at the K3NG ATU (Google K3NG TUNER). While he designed it as a balanced tuner, I have built an unbalanced version for around 20W or so. Using standard footprint 'cheap' relays. Actually the relays are the bugbear of an ATU, finding the right type and rating and low cost, since in this example there are 18 relays. From what I can see, latched relays are very expensive especially when you need 18. The trade-off is current draw, as per some posts here.

I used AD8307 Log detector chips in the SWR section. Caps used were 3kV rated 1812 sized smd although available in VK, might be harder to find in USA.

K3NG uses an Arduino NANO and a simple 2 line LCD module.? To keep size down, one of the 0.96" OLED displays might be a candidate.

glenn
vk3pe




--
Martin Held - AE7EU

-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
 

My 1st post. Have a look at the K3NG ATU (Google K3NG TUNER). While he designed it as a balanced tuner, I have built an unbalanced version for around 20W or so. Using standard footprint 'cheap' relays. Actually the relays are the bugbear of an ATU, finding the right type and rating and low cost, since in this example there are 18 relays. From what I can see, latched relays are very expensive especially when you need 18. The trade-off is current draw, as per some posts here.

I used AD8307 Log detector chips in the SWR section. Caps used were 3kV rated 1812 sized smd although available in VK, might be harder to find in USA.

K3NG uses an Arduino NANO and a simple 2 line LCD module.? To keep size down, one of the 0.96" OLED displays might be a candidate.

glenn
vk3pe

K3NG_ATU_QRP_VK3PE_BUILT_sept_2016_12.JPG
K3NG_ATU_QRP_VK3PE_BUILT_sept_2016_13.JPG
K3NG_ATU_QRP_VK3PE_BUILT_sept_2016_14.JPG

 

¿ªÔÆÌåÓý

I am available as a Beta tester as well.

?

v/r

Fred W4JLE

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Paul Schumacher via Groups.Io
Sent: Sunday, December 31, 2017 15:43
To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

?

I am willing to beta test.

?

Paul K0ZYV

?

From: Steve Black via Groups.Io <kb1chu@...>
To: [email protected]
Sent: Sunday, December 31, 2017 10:35 AM
Subject: Re: [BITX20] Tuner? Well Sure!

?

?

On 12/31/2017 11:26 AM, K9HZ wrote:

Well my company will manufacture the tuner, but i will need a bunch of beta testers to work any bugs out. ?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton - J68HZ

Soufriere, St. Lucia W.I.

Rent it:

?

email:??bill@...

?


On Dec 31, 2017, at 8:10 AM, Gordon Gibby <ggibby@...> wrote:

?If you guys make this happen, I'm going to be rather amazed.? ?Even if it merely does a clunky search search search algorithm in the beginning......

?

It can later do the intellituner thing with the smith chart type calculations.? ?

?

I'm able to actuate my MFJ 993B intellituner easily on 80 meters and usually on 40 and sometimes higher with my uBitx running just 12 volts to the finals and doing digital.? ?But that thing was about $270...........

?

As Ashhar pointed out....someone should form a company.? ?Crowd-fund it if you wish.? ? Get printed circuit boards.? (I even learned how to do that!)? ?think about how to make sure it works for every possible mode & application.....

?

For scanning systems like WINLINK, it would be wonderful if it could move to memory positions on RECEIVE (which means the VFO has to output something, or you have to use a frequency counter to watch it)

?

For ALE, the freuqncy changes are TOO FAST to follow with relays.

?

Cheers.

gordon

?

?

From: [email protected] <[email protected]> on behalf of Jack Purdum via Groups.Io <jjpurdum@...>
Sent: Sunday, December 31, 2017 8:55 AM
To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

?

I agree with Rod...it should have its own Nano. The issue really isn't the processing power, but the ?BITX I/O lines are pretty scarce. Plus, you can buy the Nano for $3, so why not? Finally, it would make the software development a little easier since could be run "alone" during testing.

?

Jack, W8TEE

?

From: Rod Self <km6sn@...>
To: [email protected]
Sent: Sunday, December 31, 2017 2:50 AM
Subject: Re: [BITX20] Tuner? Well Sure!

?

William,

Count me in.

I would be inclined to implement it it a separate case to be used with other rigs,also.

What are your (er) current thoughts on separate Nano vs integrate into ubitx's Nano?

Hope it has its own Nano, and does not rely on the ubitx. No problem if not, I can simply supply a Nano and make the tuner believe it is 'talking' to the ubitx.

Maybe I will come up with a stand-alone-controller-project for your tuner, so it can be driven with two wires, start and done.

I am interested in supporting this project.

Regards,

Rod KM6SN




On 12/29/2017 07:05 AM, K9HZ wrote:

So after finishing up most of my projects a few days ago¡­ I really needed something to do¡­ so I put on the drawing board¡­ a 100w automatic tuner that can work with the uBITx (intended to go inside the same case actually) that provides power, SWR, band memory for same antennas, low power tune, bypass, etc. all in a kit form for about $30.? I¡¯m prototyping the think now and will work on the tuning/communications code (to integrate into the Raduino) shortly.? I¡¯ve contacted a few of you off-channel to work out some protocol/communication issues¡­? but Stay tuned (double play on words there)! ???

?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

Like us on Facebook!

?

?

email:? bill@...

?

From: [email protected] [mailto:[email protected]] On Behalf Of Gordon Gibby
Sent: Friday, December 29, 2017 8:21 AM
To: [email protected]
Subject: Re: [BITX20] ALE, WINLINK and uBitX

?

Good pickups!

?

So the ALE (automatic link establishment) crowd, much like the WINLINK crowd, tend to use LOTS of bands....and thus they find ways to make their antenna systems work on mulltiple bands.? ?Here are some of the most popular ways:

?

1.? ?Fan Dipoles (time honored technique of tying multiple dipoles together at the CENTER, and the energy tends to go to the correct one, since all the others present much higher impedances.? ?The wires "fan" out with usually wooden spreaders at the? end and some string involved to keep them somewhat separate.? ?Been there done that many times, my college ham club has a 3-band unit up on the top of an 11 story building rightnow that I built for them.? ?Build for yourself, dirt cheap.?

?

2.? Auto-tuners? --- everyone makes these now and many can tune as soon as they see RF, or even return to previous settings that were memorized.? ?LDG,? and others.? ?Low power versions for $100? ?End fed wire to balanced line fed dipoles---they work with lots of different kinds of wire.?

?

3.? Inherently multiband antennas:? ?example, full wavelength loops.? ?Build for yourself.? ?

?

4.? Carefully tuned end-fed transformer-fed antennas --- there are now several of these on the market and they give an acceptable SWR on mulltiple harmonically related bands.? ?Tend to be close to $100

?

5.? (the one I dislike)? resistively terminated folded dipoles --- these use a resistor to make up for what a folded dipole can't create and give an SWR that is "acceptable" literally across EVERY FREQUENCY in a decade of frequencies.? ?3-30 MHz.? ?The tradeoff is loss, as much as 10 db at times.? And they generally are pricey.

?

6.? There are some multi-band vertical antennas on the market that are basically vertical fan dipoles, but scrunched up in a nice package.? ?An elderly ham in my city has one, 32 feet tall....a gang of us put it up and doggone it does from from 40 meters all the way through 6 meters

?

?

And there are probably many more....

?

Gordon

From: [email protected] <[email protected]> on behalf of Arvo KD9HLC via Groups.Io <arvopl@...>
Sent: Friday, December 29, 2017 9:12 AM
To: [email protected]
Subject: Re: [BITX20] ALE, WINLINK and uBitX

?

An automatic tuner protects the rig during TX.? If the SWR is bad during TX, some of the signal coming out of the transmitter is reflected by the antenna back into the radio where it can cause damage.

That said, RX is optimized by a properly tuned antenna, but some good amount of signal still makes into the radio when receiving, even when the antenna is not perfect.

So I assume Doc G? is scanning for radio traffic, and then when he finds some if he wants to transmit he does something about his SWR for that frequency.

?

?

?

Virus-free.

?

?
 

I have been following this thread with interest ... I think latching relays are the way to go, but certainly cost is also important and higher amperage latching relays are not so cheap.

I have been pondering for a while about combining an automatic antenna tuner and antenna switching device.? Settings for both are dependent on frequency, ?but the two interplay.? Changing antenna changes the optimal match.

Outputting the frequency from the Bitx arduino should result in preselection of relays associated with previously confirmed optimal settings by frequency and antenna.? This could potentially allow relay selection by to meet the 1/5 second target for ALE as even latching relays can stabilize in about 50ms.

The other essential is a TX inhibit so that relays do not change state with a carrier present, ?that is, if you want them to last a few years ...

Mike ZL1AXG


On Mon, 1 Jan 2018 at 10:53 AM, K9HZ <bill@...> wrote:

Looking into that¡­ same board but populated with a different relay.? I think it¡¯s doable, but It could make the base case kit more expensive¡­ because the cheap (but very adequate) non-latching relays I use don¡¯t have latching counter parts.? I have a friend in the Electronic Parts Sales business at a major distributor¡­ he may be able to find something that works for us.

?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

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?

email:? bill@...

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From: [email protected] [mailto:[email protected]] On Behalf Of M Garza
Sent: Sunday, December 31, 2017 3:13 PM


To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

?

Or provide the latching relays as an option.

?

Marco - KG5PRT?

?




?

image001.gif

Diver Martin
 

Ah, you're designing for 100W and some pretty low impedances.? I'm not designing for that much power / mismatch I guess :)? 10ohms, 50W, which is close enough for me and can still tune an SWR of 5:1, and my real goal is 3:1.? For a uBitx at 10W output drive, you could use significantly less current rating imho.

On Sun, Dec 31, 2017 at 1:46 PM, K9HZ <bill@...> wrote:

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.

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

Like us on Facebook!

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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!

?

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.?

?

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.

?

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.

?

<< 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.

?

<< 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.

?

<<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 !!!?

?

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).

?

?

?

?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

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!

?

Hi,??

?

WINLINK and ALE are two different animals.

?

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.

?

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

?

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.

?

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

?

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.....

?

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.

?

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.

?

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.

?

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

?

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!

?

Gordon

?



?

--

Martin Held - AE7EU


-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?




--
Martin Held - AE7EU

-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
 

¿ªÔÆÌåÓý

Looking into that¡­ same board but populated with a different relay.? I think it¡¯s doable, but It could make the base case kit more expensive¡­ because the cheap (but very adequate) non-latching relays I use don¡¯t have latching counter parts.? I have a friend in the Electronic Parts Sales business at a major distributor¡­ he may be able to find something that works for us.

?

?

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

?

Owner - Operator

Big Signal Ranch ¨C K9ZC

Staunton, Illinois

?

Owner ¨C Operator

Villa Grand Piton ¨C J68HZ

Soufriere, St. Lucia W.I.

Rent it:

Like us on Facebook!

?

?

email:? bill@...

?

From: [email protected] [mailto:[email protected]] On Behalf Of M Garza
Sent: Sunday, December 31, 2017 3:13 PM
To: [email protected]
Subject: Re: [BITX20] Tuner? Well Sure!

?

Or provide the latching relays as an option.

?

Marco - KG5PRT?

?




?

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