Date   

40 AND 80 METER NET REPORT

Johnny AC0BQ
 

Ge Group:
The band conditions were not very net friendly tonight.
I had some friendly competition from the NA sprint and i had to move up to 3.564.5. 


40 Meter check in's were: 
WA9PWP PAUL 
K3NLT RUSS 

80 METER NET REPORT
N0YJ BERT 
WA9PWP PAUL 
K3NLT RUSS
Thanks Guys, Stay well! 
72 Johnny AC0BQ 

--
QRP....."More smiles per Watt"
72
JOHNNY AC0BQ  ..



Wednesday Evening 40 and 80 meter Nets - Wed, 03/18/2020 #cal-notice

main@4SQRP.groups.io Calendar <noreply@...>
 

Wednesday Evening 40 and 80 meter Nets

When:
Wednesday, 18 March 2020
8:00pm to 9:00pm
(GMT-05:00) America/Chicago

Where:
40 and 80 Meters

Organizer:
jomatlock@...

Description:
The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP Operator to be determined.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


Upcoming Event: Wednesday Evening 40 and 80 meter Nets - Wed, 03/18/2020 8:00pm-9:00pm #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: Wednesday Evening 40 and 80 meter Nets

When: Wednesday, 18 March 2020, 8:00pm to 9:00pm, (GMT-05:00) America/Chicago

Where:40 and 80 Meters

View Event

Organizer: jomatlock@...

Description: The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP Operator to be determined.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


Re: Fire In The Wire

Curt
 

I have had good luck with 1-5W on 20M with 34' wire up in a tree tuned with a KI6J Tuner that predated the Sota tuner.  Use it from my patio when weather n bugs permit,  Used it portable from Northern Ontario a decade ago with an ATS-3 @ 1W, made lot of contacts into all parts of the US from inside a cabin as the bugs never allowed outside.

My 2 cents.

Curt KB5JO


Re: Fire In The Wire

Jim Upson
 

Check out this site....FANTASTIC insight on building a Type 43 transformer....


especially go to the first link on page 1 From the above link.....here it is just to emphasize it....



73, Jim / AC3B 


On Wed, Mar 18, 2020 at 11:00 AM Joshua Wood <WoodJRx@...> wrote:
Thank you all for your ideas and recommendations,  in this thread and all the splintered ones, private and public!  My wife had minor sinus surgery, and I work in a hospital,  so I've been a bit preoccupied.   I'm definitely going to go through the responses as soon as I  can!

-Josh
W0ODJ 

On Mon, Mar 16, 2020, 14:10 Gwen Patton <ardrhi@...> wrote:
From the consensus here, I think I'll make myself another full-sized W3EDP End-fed and try that next time I go operate at the park. It'll have to be when the parks are actually OPEN again, as the recent COVID-19 quarantine effort has caused them all to be closed, at least in my neck of the woods. That's literally...one of the parks in question is a humongous farm with big wooded areas here and there with trails throughout it. It's called the Norristown Farm Park, KFF-4363, and it's my favorite since it's only a mile or so from me. One of the side parking lots has a couple of handicapped spaces my van will fit into, and has a picnic table under a small shelter just 50-75 feet from the parking lot, so I can roll my little flat roller cart over there from my van and set up. There's plenty of room, a flat, grassy area, that I usually use for my wire antennas next to the table, so I set up my antenna, then set up the station under the shelter, and begin operating. The only end-fed I've used there so far is the SOTABeams end-fed with the built-in 20/30/40 tuner, and that works reasonably well. But I may just try a W3EDP this spring with my Elecraft T1 tuner and see what results I get.

I've got other experiments on the burner as well, including a dipole made of electric fence strap -- 15 parallel stainless-steel wires woven lengthwise into a 2" wide strap of poly webbing. It's used to make some fantastically wide-bandwidth single band dipoles, so I want to see if I can make a fan dipole using the stuff. There may be too much coupling between the wires, but it's worth a try. It might just need a lot of trimming to overcome the coupling. If that's the case, I may be able to make a decent multi-band fan dipole that's simpler to erect. I'd model it, but frankly, I don't yet know how to use the modeling software. I've got several programs, but they're so much Greek to me! hi hi

73
Gwen, NG3P

On Mon, Mar 16, 2020 at 2:38 PM Tim N9PUZ <tim.n9puz@...> wrote:
I am a big fan of end fed antennas for portable use as well. Even when I
am in a wooded area I usually use my 31' or 28' Jackite pole as a
support. I attach the wire to the tip, extend the mast to its full
height, and then just let it lean into a tree.

Tim N9PUZ

On 3/16/2020 10:36 AM, Nick Kennedy wrote:
> Getting back to the original poster - I like the EFHW for field
> operations because it only needs one support. I'm a total klutz when
> it comes to getting lines through trees. I also like the Jackite pole
> (31') as a support.






--

-+-+-+-+-
Jenny Everywhere's Infinite: Quark Time
http://quarktime.net


Re: For Sale

bobby rolph
 

 This is just a reminder that I still have both Hilltoppers for sale. 73
Bobby
KB4QNR


Re: Fire In The Wire

Joshua Wood
 

Thank you all for your ideas and recommendations,  in this thread and all the splintered ones, private and public!  My wife had minor sinus surgery, and I work in a hospital,  so I've been a bit preoccupied.   I'm definitely going to go through the responses as soon as I  can!

-Josh
W0ODJ 

On Mon, Mar 16, 2020, 14:10 Gwen Patton <ardrhi@...> wrote:
From the consensus here, I think I'll make myself another full-sized W3EDP End-fed and try that next time I go operate at the park. It'll have to be when the parks are actually OPEN again, as the recent COVID-19 quarantine effort has caused them all to be closed, at least in my neck of the woods. That's literally...one of the parks in question is a humongous farm with big wooded areas here and there with trails throughout it. It's called the Norristown Farm Park, KFF-4363, and it's my favorite since it's only a mile or so from me. One of the side parking lots has a couple of handicapped spaces my van will fit into, and has a picnic table under a small shelter just 50-75 feet from the parking lot, so I can roll my little flat roller cart over there from my van and set up. There's plenty of room, a flat, grassy area, that I usually use for my wire antennas next to the table, so I set up my antenna, then set up the station under the shelter, and begin operating. The only end-fed I've used there so far is the SOTABeams end-fed with the built-in 20/30/40 tuner, and that works reasonably well. But I may just try a W3EDP this spring with my Elecraft T1 tuner and see what results I get.

I've got other experiments on the burner as well, including a dipole made of electric fence strap -- 15 parallel stainless-steel wires woven lengthwise into a 2" wide strap of poly webbing. It's used to make some fantastically wide-bandwidth single band dipoles, so I want to see if I can make a fan dipole using the stuff. There may be too much coupling between the wires, but it's worth a try. It might just need a lot of trimming to overcome the coupling. If that's the case, I may be able to make a decent multi-band fan dipole that's simpler to erect. I'd model it, but frankly, I don't yet know how to use the modeling software. I've got several programs, but they're so much Greek to me! hi hi

73
Gwen, NG3P

On Mon, Mar 16, 2020 at 2:38 PM Tim N9PUZ <tim.n9puz@...> wrote:
I am a big fan of end fed antennas for portable use as well. Even when I
am in a wooded area I usually use my 31' or 28' Jackite pole as a
support. I attach the wire to the tip, extend the mast to its full
height, and then just let it lean into a tree.

Tim N9PUZ

On 3/16/2020 10:36 AM, Nick Kennedy wrote:
> Getting back to the original poster - I like the EFHW for field
> operations because it only needs one support. I'm a total klutz when
> it comes to getting lines through trees. I also like the Jackite pole
> (31') as a support.






--

-+-+-+-+-
Jenny Everywhere's Infinite: Quark Time
http://quarktime.net


Upcoming Event: Wednesday Evening 40 and 80 meter Nets - Wed, 03/18/2020 8:00pm-9:00pm #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: Wednesday Evening 40 and 80 meter Nets

When: Wednesday, 18 March 2020, 8:00pm to 9:00pm, (GMT-05:00) America/Chicago

Where:40 and 80 Meters

View Event

Organizer: jomatlock@...

Description: The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP Operator to be determined.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


Re: Si5351 audio pops and PLL Lockups

Dave Benson
 

Ron-

Without knowing what's in your firmware, I'll comment on those bypass caps to ground at the encoder.  When the contacts are in the 'open' state, the caps are being charged to 5V through a pullup resistor.  When the contacts close, though, the charge on the caps is discharged to ground at a pretty high instantaneous current.  That's a source of unwanted noise.  It can be remedied by adding a fairly low resistance (say, 100 ohms) in series from the caps to the encoder contacts.

If you're using a high-resolution encoder, there's an off chance you're generating frequency updates faster than the Si5351 can accept them.  Not sure what it would do then.  My recollection is that the updates take 5-10 milliseconds. It may also help to command the Si5351 outputs 'off' prior to any update and restore them only after the command sequence is complete. I was working with an earlier version of NT7S's library, though, and haven't kept current on newer library versions.

73- Dave,  K1SWL



Virus-free. www.avast.com


On Tue, Mar 17, 2020 at 9:09 AM WB9YZU via Groups.Io <wb9yzu=yahoo.com@groups.io> wrote:
Hi Folks, I'm sure you folks have fielded this question before, but search results haven't been very fruitful.
My rig is a Forty-9er that I have modified to accept a VFO instead of a XTAL. I based the idea from a 2016 article in QST where the author used a I2C DDS and a parallel display.

I decided to take on the design and programming of the Arduino backbone myself and went with a Si5351a and put the display on the I2C bus via an adapter card that just piggybacks on the display. Nothing fancy. I'm using an inexpensive digital encoder to change frequencies.

The frequency is constantly being updated to the Si5351a, this is because keying requires that I change from a receive to a transmit frequency on the fly, and to avoid transmitting while the Si5351 is changing frequencies, I am keying the Forty-9er with the Arduino.

Everything seems to work pretty well, the radio does what it's supposed to do, and I have made a number of nice QSOs.
However the enjoyment is somewhat muted by this annoying popping and PLL dropout when dialing the rig.
When the PLL goes to lunch, I can't recover and I need to reset the radio. Though the symptom can appear most anywhere, it is much more prevalent around 7.055.

Steps I've taken do date:
Scoured the code and internet for clues. I am on my NthX2 attempt to write a decent code, the last attempt actually made it worse!
I verified that I am using the latest Etherkit Si5351a Library; version 2.1.4.
I tried to debounce the encoder by using an interrupt call and a debounce routine on the interrupt.; I also added .01uf caps across the encoder CLK and DT Lines to GND.

I read that the LCD is a noise source, so I installed 100uh coils on the power feed (+ & -)  to the display board. That cleaned up some audio noise.

From the number of Si5351a based QRP rigs, I assume a solution(s) has been found? What has worked for you folks?
--
, Ron WB9YZU


Re: Si5351 audio pops and PLL Lockups

Nick Kennedy <kennnick@...>
 

Hoo boy, the joys of programming up a synthesizer for your rig!

I've been doing a lot of programming on a Si5351a with I & Q outputs recently but haven't had it actually connected to a receiver much as yet.

However, doing similar things with a Si570 I have heard that noise while tuning. It can be pretty pronounced and distracting but I'm grateful it's gone when I stop turning the knob.

In the early days of the KX3, Elecraft was fielding a lot of questions about this. The noise was referred to as "zipper noise".  Theirs was again an Si570 and the noise wasn't loud but was noticeable. I think they mainly used careful routing of certain wires to mitigate it. This may have been the I2C signals, I don't remember for sure.

Since it might come from one or more of three areas, you might try software experiments to see which makes the noise, or makes the most noise.  

First, have your encoder signals active but your MCU not sending any Si5351a control signals or LCD updates.

Next, have your MCU continuously updating the Si5351a with no encoder input and no LCD updates.

Third, have the MCU continuously updating the LCD with no encoder or data to the Si5351a happening.

As far as the chip losing PLL synch ... I'm not sure I've seen that on my Si5351a project but I used to see it some with the Si570 and I concluded it was RF interference. If my output from the chip was unterminated I'd have the problem, but if it were properly terminated, it did not occur. I think this happened mostly at VHF though.

In my current I/Q Si5351a project, I'm adding the bells and whistles to make it into a full featured VFO with things like band selection and having a keyed line input to tell it when to do the offset shift, plus RIT. 

As far as shifting between TX and RX goes ... it works fine but I realized a bit late I could have used the 3rd clock to go to the TX while the other two provide I & Q for the RX and there would be no need for switching when going from RX to TX and back.

I'm not using a library for the Si5351a control, which makes it easier to examine the code. I do have libraries for LCD and Wire (I2C).

73-

Nick, WA5BDU


On Tue, Mar 17, 2020 at 8:09 AM WB9YZU via Groups.Io <wb9yzu=yahoo.com@groups.io> wrote:
Hi Folks, I'm sure you folks have fielded this question before, but search results haven't been very fruitful.
My rig is a Forty-9er that I have modified to accept a VFO instead of a XTAL. I based the idea from a 2016 article in QST where the author used a I2C DDS and a parallel display.

I decided to take on the design and programming of the Arduino backbone myself and went with a Si5351a and put the display on the I2C bus via an adapter card that just piggybacks on the display. Nothing fancy. I'm using an inexpensive digital encoder to change frequencies.

The frequency is constantly being updated to the Si5351a, this is because keying requires that I change from a receive to a transmit frequency on the fly, and to avoid transmitting while the Si5351 is changing frequencies, I am keying the Forty-9er with the Arduino.

Everything seems to work pretty well, the radio does what it's supposed to do, and I have made a number of nice QSOs.
However the enjoyment is somewhat muted by this annoying popping and PLL dropout when dialing the rig.
When the PLL goes to lunch, I can't recover and I need to reset the radio. Though the symptom can appear most anywhere, it is much more prevalent around 7.055.

Steps I've taken do date:
Scoured the code and internet for clues. I am on my NthX2 attempt to write a decent code, the last attempt actually made it worse!
I verified that I am using the latest Etherkit Si5351a Library; version 2.1.4.
I tried to debounce the encoder by using an interrupt call and a debounce routine on the interrupt.; I also added .01uf caps across the encoder CLK and DT Lines to GND.

I read that the LCD is a noise source, so I installed 100uh coils on the power feed (+ & -)  to the display board. That cleaned up some audio noise.

From the number of Si5351a based QRP rigs, I assume a solution(s) has been found? What has worked for you folks?
--
, Ron WB9YZU


Si5351 audio pops and PLL Lockups

WB9YZU
 

Hi Folks, I'm sure you folks have fielded this question before, but search results haven't been very fruitful.
My rig is a Forty-9er that I have modified to accept a VFO instead of a XTAL. I based the idea from a 2016 article in QST where the author used a I2C DDS and a parallel display.

I decided to take on the design and programming of the Arduino backbone myself and went with a Si5351a and put the display on the I2C bus via an adapter card that just piggybacks on the display. Nothing fancy. I'm using an inexpensive digital encoder to change frequencies.

The frequency is constantly being updated to the Si5351a, this is because keying requires that I change from a receive to a transmit frequency on the fly, and to avoid transmitting while the Si5351 is changing frequencies, I am keying the Forty-9er with the Arduino.

Everything seems to work pretty well, the radio does what it's supposed to do, and I have made a number of nice QSOs.
However the enjoyment is somewhat muted by this annoying popping and PLL dropout when dialing the rig.
When the PLL goes to lunch, I can't recover and I need to reset the radio. Though the symptom can appear most anywhere, it is much more prevalent around 7.055.

Steps I've taken do date:
Scoured the code and internet for clues. I am on my NthX2 attempt to write a decent code, the last attempt actually made it worse!
I verified that I am using the latest Etherkit Si5351a Library; version 2.1.4.
I tried to debounce the encoder by using an interrupt call and a debounce routine on the interrupt.; I also added .01uf caps across the encoder CLK and DT Lines to GND.

I read that the LCD is a noise source, so I installed 100uh coils on the power feed (+ & -)  to the display board. That cleaned up some audio noise.

From the number of Si5351a based QRP rigs, I assume a solution(s) has been found? What has worked for you folks?
--
, Ron WB9YZU


Re: SSB-Mite Question

ohwenzelph
 

It is interesting, the hi-per-mite has 8 plastic film caps which in some circles are valued at audio frequencies over other kinds. It’s not clear to me what kind and how much of a difference it makes and when to use them. My guess is that Dave actually understands it and might shed some light.
thanks
jer


Upcoming Event: Wednesday Evening 40 and 80 meter Nets - Wed, 03/18/2020 8:00pm-9:00pm #cal-reminder

main@4SQRP.groups.io Calendar <main@...>
 

Reminder: Wednesday Evening 40 and 80 meter Nets

When: Wednesday, 18 March 2020, 8:00pm to 9:00pm, (GMT-05:00) America/Chicago

Where:40 and 80 Meters

View Event

Organizer: jomatlock@...

Description: The 40 Meter Net will be at 8:00 pm central time  on 7.122 +-. QRM
NCS is WQ5RP Operator to be determined.

Wednesday evening 80 Meter CW Net. will be at  (8:30PM Central Time Wednesday). 
The 80 meter net will be called on 3.564 MHz +/- QRM.
Net control operators are Johnny AC0BQ or Paul N0NBD.

* NEW *  Wednesday evening DMR Voice Net will be at (Thursday) 0300 UTC (9:00PM Central Time Wednesday/)
Four States QRP has a Brandmeister DMR Talk Group (TG31654). Join us to discuss QRP, ask questions, or just ragchew. The Wednesday net is a directed net  but any other time you may use the Talk Group to chat with other QRPers.
Net Control operator is Bert NØYJ.


For Sale

bobby rolph
 

Hello. I have a couple of Hilltoppers for sale. Both units are already assembled and working properly. I have one 40m and one 20m transceivers. I am asking $80 for each unit of $150 if you would like to purchase both. I will cover the shipping for the US lower 48 states. I am selling to fund a new project. Just email me privately if you are interested. 73
KB4QNR
Bobby Rolph


Re: Test build on 'Circ-Key' - found a problem to report

nm0s_qrp <ai9e_qrp@...>
 

What you discovered is a _feature_! The battery power is only connected when the cable is plugged in. That way you can power down the keyer without having to disconnect the battery.


Test build on 'Circ-Key' - found a problem to report

wa2cky
 

Not sure if there is anyone, in particular, that I should sent this to but I did find a 'bug' in the pc board.  Not critical as it was easily fixed but none-the-less should be noted.

Problem: the battery negative terminal is NOT routed to the 'ground' layer on the board. The '-9V' only goes to the Key Output jack and not to any of the other 'ground' connections (e.g. the U1-8 and U2-7).

Fix was easy - a short piece of wire from the 9V battery negative connection to the mounting hole/ground layer about a 1/4" away. 

Now back to the testing.

Bob, WA2CKY


Re: Fire In The Wire

Gwen Patton
 

From the consensus here, I think I'll make myself another full-sized W3EDP End-fed and try that next time I go operate at the park. It'll have to be when the parks are actually OPEN again, as the recent COVID-19 quarantine effort has caused them all to be closed, at least in my neck of the woods. That's literally...one of the parks in question is a humongous farm with big wooded areas here and there with trails throughout it. It's called the Norristown Farm Park, KFF-4363, and it's my favorite since it's only a mile or so from me. One of the side parking lots has a couple of handicapped spaces my van will fit into, and has a picnic table under a small shelter just 50-75 feet from the parking lot, so I can roll my little flat roller cart over there from my van and set up. There's plenty of room, a flat, grassy area, that I usually use for my wire antennas next to the table, so I set up my antenna, then set up the station under the shelter, and begin operating. The only end-fed I've used there so far is the SOTABeams end-fed with the built-in 20/30/40 tuner, and that works reasonably well. But I may just try a W3EDP this spring with my Elecraft T1 tuner and see what results I get.

I've got other experiments on the burner as well, including a dipole made of electric fence strap -- 15 parallel stainless-steel wires woven lengthwise into a 2" wide strap of poly webbing. It's used to make some fantastically wide-bandwidth single band dipoles, so I want to see if I can make a fan dipole using the stuff. There may be too much coupling between the wires, but it's worth a try. It might just need a lot of trimming to overcome the coupling. If that's the case, I may be able to make a decent multi-band fan dipole that's simpler to erect. I'd model it, but frankly, I don't yet know how to use the modeling software. I've got several programs, but they're so much Greek to me! hi hi

73
Gwen, NG3P

On Mon, Mar 16, 2020 at 2:38 PM Tim N9PUZ <tim.n9puz@...> wrote:
I am a big fan of end fed antennas for portable use as well. Even when I
am in a wooded area I usually use my 31' or 28' Jackite pole as a
support. I attach the wire to the tip, extend the mast to its full
height, and then just let it lean into a tree.

Tim N9PUZ

On 3/16/2020 10:36 AM, Nick Kennedy wrote:
> Getting back to the original poster - I like the EFHW for field
> operations because it only needs one support. I'm a total klutz when
> it comes to getting lines through trees. I also like the Jackite pole
> (31') as a support.






--

-+-+-+-+-
Jenny Everywhere's Infinite: Quark Time
http://quarktime.net


Re: Fire In The Wire

Tim N9PUZ
 

I am a big fan of end fed antennas for portable use as well. Even when I am in a wooded area I usually use my 31' or 28' Jackite pole as a support. I attach the wire to the tip, extend the mast to its full height, and then just let it lean into a tree.

Tim N9PUZ

On 3/16/2020 10:36 AM, Nick Kennedy wrote:
Getting back to the original poster - I like the EFHW for field operations because it only needs one support. I'm a total klutz when it comes to getting lines through trees. I also like the Jackite pole (31') as a support.


Re: Fire In The Wire

Jim Upson
 

Yes...I personally think it makes sense - as I stated 1000’s if hams use Type 43 for matching units....so I can’t believe it is a bad choice...just maybe not as optimal as it can be....

However.....as I want to reiterate....I am not technically skilled....but I believe KX0R is very technical (see his QRZ page)......so I wanted to share his thoughts in case others had not seen it...and to get your feedback....so THANK YOU for the response!

Once I build a Type 43 and a KX0R version I am hoping some power meter results and RBN spots will confirm the level of effectiveness differences....maybe it will be subtle....maybe significant....time will tell. :-)

Again....I am open to all solutions at this point....not sure what’s Josh is interested in trying...

THANK YOU for your comments....it does help me learn as I go...

73, Jim/ AC3B 


On Mon, Mar 16, 2020 at 12:16 PM John <ve3ips@...> wrote:
Jim

what shall we use if 43 is no good?   I learned a lot from your post and maybe i will just stick with a dipole to keep it ya'll ya'll simple simple

I also spent a lot of bench time working with type 43 and 61 transformers. Type 43 is so lossy that it’s hard to measure a resonant frequency in a tuned circuit. It’s really designed for broadband transmission line transformers and EMI suppression chokes. It’s not a good choice for conventional transformers. Many of the people posting here don’t seem to know what these terms mean. I would not use type 43 to feed the antenna in my SOTA systemThe reason some antennas use it is that its loss hides the mismatch errors in the system! It lowers SWR by adding loss  


John VE3IPS

Ham Radio is a lifestyle not a Hobby!
Take the radio outside and operate from the Field




On Mon, Mar 16, 2020 at 11:36 AM Nick Kennedy <kennnick@...> wrote:
Boy, a lot of good info in there Jim. Thanks for taking the time to put it all together.

One point I'll take a bit of an issue with is the suitability (or not) of ferrites such as type 43 for antenna matching transformers.

It's true that the Q can be as low as 1 at HF which can make one wonder how it can possibly be good for anything other than a choke at those frequencies. But it can. My explanation is that most of the losses are core losses caused by the flux in the core. But in a transformer with a high coupling coefficient, flux in the core is minimized and such losses are not excessive.

Your source suggested that with his allowance for transmission line transformers but I think it can be true for conventional transformers and autotransformers as well, although maybe not to the same extent.

Measurements should tell the tale. I did some with FT-114-43 transformers designed for EFHW matching a few years ago  and see losses on the order of 1 dB for 40 through 20. Not negligible but not prohibitive either.

The huge crowd of users of the currently popular homebrew version of the MyAntennas EFHW are using large diameter ferrite cores such as FT-240 to reduce losses as well as handle more power. They've also transitioned from type 43 to type 52 which does lower losses some more. 

Getting back to the original poster - I like the EFHW for field operations because it only needs one support. I'm a total klutz when it comes to getting lines through trees. I also like the Jackite pole (31') as a support.

73,

Nick, WA5BDU


Re: Fire In The Wire

John
 

Jim

what shall we use if 43 is no good?   I learned a lot from your post and maybe i will just stick with a dipole to keep it ya'll ya'll simple simple

I also spent a lot of bench time working with type 43 and 61 transformers. Type 43 is so lossy that it’s hard to measure a resonant frequency in a tuned circuit. It’s really designed for broadband transmission line transformers and EMI suppression chokes. It’s not a good choice for conventional transformers. Many of the people posting here don’t seem to know what these terms mean. I would not use type 43 to feed the antenna in my SOTA systemThe reason some antennas use it is that its loss hides the mismatch errors in the system! It lowers SWR by adding loss  


John VE3IPS

Ham Radio is a lifestyle not a Hobby!
Take the radio outside and operate from the Field




On Mon, Mar 16, 2020 at 11:36 AM Nick Kennedy <kennnick@...> wrote:
Boy, a lot of good info in there Jim. Thanks for taking the time to put it all together.

One point I'll take a bit of an issue with is the suitability (or not) of ferrites such as type 43 for antenna matching transformers.

It's true that the Q can be as low as 1 at HF which can make one wonder how it can possibly be good for anything other than a choke at those frequencies. But it can. My explanation is that most of the losses are core losses caused by the flux in the core. But in a transformer with a high coupling coefficient, flux in the core is minimized and such losses are not excessive.

Your source suggested that with his allowance for transmission line transformers but I think it can be true for conventional transformers and autotransformers as well, although maybe not to the same extent.

Measurements should tell the tale. I did some with FT-114-43 transformers designed for EFHW matching a few years ago  and see losses on the order of 1 dB for 40 through 20. Not negligible but not prohibitive either.

The huge crowd of users of the currently popular homebrew version of the MyAntennas EFHW are using large diameter ferrite cores such as FT-240 to reduce losses as well as handle more power. They've also transitioned from type 43 to type 52 which does lower losses some more. 

Getting back to the original poster - I like the EFHW for field operations because it only needs one support. I'm a total klutz when it comes to getting lines through trees. I also like the Jackite pole (31') as a support.

73,

Nick, WA5BDU