Date   

Re: FSL coil Q of 1162/46 and 660/46 (added 330/46) Litz compared using HP4342A Q meter

Steve Ratzlaff
 

I wound a coil using 330/46 Litz to compare with the other two. 21 turns gave 273.3 uH, quite a bit higher than the other two due to the narrower width coil. Probably 1 or 2 turns should be removed for use in an actual FSL with 385 pF tuning cap.

On 7/5/2020 3:46 PM, STEVE wrote:

This experiment compares a ferrite sleeve coil of 1162/46 Litz with a ferrite sleeve coil of 660/46, both 21 turns with final coil diameter about 6 3/8", using 140 mm ferrite rods in the ferrite sleeve. The same ferrite sleeve was used for both coils, with the coils centered on the sleeve for peak inductance. The 1162/46 coil measured 236.5 uH; the 660/46 coil measured 253 uH for the same 21 turns for each. (The fatter Litz will have a little less inductance compared to the thinner Litz for the same number of turns due to being a wider coil.)

Each ferrite sleeve coil was suspended 7" above the Q meter deck, oriented horizontally; each coil had about 12" of pigtail length. The HP4342A Q meter capacitor (very high Q) was used to resonate each coil. Solid copper lugs were used on the ends of each coil to connect the coil to the Q meter. Coil Q should directly relate to signal level coupled to the receiver with higher Q giving higher signal level. Since the Q meter's variable capacitor was used, which has much higher Q than any external variable capacitor I'm aware of, this removes the external capacitor Q effects from the experimental results, only comparing the two Litz types.

73,

Steve AA7U

                          1162/46    660/46    330/46

1700 kHz  305Q        310Q     263Q

1600 kHz  345Q        350Q     300Q

1500 kHz  385Q        395Q     340Q

1400 kHz  440Q        445Q     380Q

1300 kHz  500Q        500Q     433Q

1200 kHz  565Q        570Q     490Q

1100 kHz  643Q        645Q     555Q

1000 kHz  740Q        730Q     630Q

900 kHz   840Q        835Q     710Q

800 kHz   955Q        930Q     785Q

700 kHz   1116Q       1084Q    860Q

600 kHz   1246Q       1144Q    910Q

550 kHz   1301Q       1173Q    925Q

520 kHz   1332Q       1186Q    925Q

510 kHz---------------1188Q    928Q (340 pF for 330/46)


Re: FSL coil Q of 1162/46 and 660/46 Litz compared using HP4342A Q meter

Steve Ratzlaff
 

I should add that my 140mm ferrite rods are Chinese rods, not Russian rods, and that the results may be different using Russian rods. I don't have enough Russian rods to do the experiment using them. Gary's latest 6" FSL with Russian rods used 19 turns of the 1162/46 Litz where mine used 21 turns.

Steve AA7U

On 7/5/2020 3:46 PM, STEVE wrote:

This experiment compares a ferrite sleeve coil of 1162/46 Litz with a ferrite sleeve coil of 660/46, both 21 turns with final coil diameter about 6 3/8", using 140 mm ferrite rods in the ferrite sleeve. The same ferrite sleeve was used for both coils, with the coils centered on the sleeve for peak inductance. The 1162/46 coil measured 236.5 uH; the 660/46 coil measured 253 uH for the same 21 turns for each. (The fatter Litz will have a little less inductance compared to the thinner Litz for the same number of turns due to being a wider coil.)

Each ferrite sleeve coil was suspended 7" above the Q meter deck, oriented horizontally; each coil had about 12" of pigtail length. The HP4342A Q meter capacitor (very high Q) was used to resonate each coil. Solid copper lugs were used on the ends of each coil to connect the coil to the Q meter. Coil Q should directly relate to signal level coupled to the receiver with higher Q giving higher signal level. Since the Q meter's variable capacitor was used, which has much higher Q than any external variable capacitor I'm aware of, this removes the external capacitor Q effects from the experimental results, only comparing the two Litz types.

73,

Steve AA7U

                            1162/46    660/46

1700 kHz  305Q        310Q

1600 kHz  345Q        350Q

1500 kHz  385Q        395Q

1400 kHz  440Q        445Q

1300 kHz  500Q        500Q

1200 kHz  565Q        570Q

1100 kHz  643Q        645Q  Q's are equal at this frequency

1000 kHz  740Q        730Q  Fatter Litz begins to have better Q

900 kHz   840Q        835Q

800 kHz   955Q        930Q

700 kHz   1116Q       1084Q

600 kHz   1246Q       1144Q

550 kHz   1301Q       1173Q

520 kHz   1332Q       1186Q

1162/46 Litz--385 pF, 516 kHz, 1333Q (max capacitance of variable cap Gary uses)

510 kHz               1188Q

660/46 Litz--385 pF, 502 kHz, 1189Q (max capacitance of variable cap Gary uses)


FSL coil Q of 1162/46 and 660/46 Litz compared using HP4342A Q meter

Steve Ratzlaff
 

This experiment compares a ferrite sleeve coil of 1162/46 Litz with a ferrite sleeve coil of 660/46, both 21 turns with final coil diameter about 6 3/8", using 140 mm ferrite rods in the ferrite sleeve. The same ferrite sleeve was used for both coils, with the coils centered on the sleeve for peak inductance. The 1162/46 coil measured 236.5 uH; the 660/46 coil measured 253 uH for the same 21 turns for each. (The fatter Litz will have a little less inductance compared to the thinner Litz for the same number of turns due to being a wider coil.)

Each ferrite sleeve coil was suspended 7" above the Q meter deck, oriented horizontally; each coil had about 12" of pigtail length. The HP4342A Q meter capacitor (very high Q) was used to resonate each coil. Solid copper lugs were used on the ends of each coil to connect the coil to the Q meter. Coil Q should directly relate to signal level coupled to the receiver with higher Q giving higher signal level. Since the Q meter's variable capacitor was used, which has much higher Q than any external variable capacitor I'm aware of, this removes the external capacitor Q effects from the experimental results, only comparing the two Litz types.

73,

Steve AA7U

                            1162/46    660/46

1700 kHz  305Q        310Q

1600 kHz  345Q        350Q

1500 kHz  385Q        395Q

1400 kHz  440Q        445Q

1300 kHz  500Q        500Q

1200 kHz  565Q        570Q

1100 kHz  643Q        645Q  Q's are equal at this frequency

1000 kHz  740Q        730Q  Fatter Litz begins to have better Q

900 kHz   840Q        835Q

800 kHz   955Q        930Q

700 kHz   1116Q       1084Q

600 kHz   1246Q       1144Q

550 kHz   1301Q       1173Q

520 kHz   1332Q       1186Q

1162/46 Litz--385 pF, 516 kHz, 1333Q (max capacitance of variable cap Gary uses)

510 kHz               1188Q

660/46 Litz--385 pF, 502 kHz, 1189Q (max capacitance of variable cap Gary uses)


Re: Gary's New 6" FSL Design

Todd
 

Thanks Gary for the detailed response.

When endeavoring to obtain the highest resonant signal output at a given frequency, the Q needs to be high as practicable. The audio fidelity will be somewhat compromised, but this can be partially improved by slightly tuning the FSL antenna to peak 1 or 2 KHz above the carrier frequency. This is why the 8:1 reduction drive is essential. 

High Q FSL antennas are the only way to obtain similar RF gain and selectivity in a small package that favorably compares to large 4 - 6 foot air core box loops. This means a 6 inch FSL can be positioned pretty much anywhere within the house. A 6 ft air core box loop positioned on the kitchen bench top is not practical. But a 6" FSL would easily sit there.

The 6" FSL with 1162/46 Litz wire will likely be more expensive for DXers outside the USA and China. I estimate the total cost for me would be around AU $250 including parts postage.

For those DXers that seek weak signals only 9 or 10 KHz adjacent to very strong locals, the high Q FSL is ideal from a 3 dB bandwidth perspective. The disadvantage is no tilting provision for reducing local signals by > 60 dB. This Kiwa loop tilting mechanism was very good for obtaining the critical tilt angle for nulling a local signal.

One possibility is to video a 6" FSL comparison test against the large 9 foot air core loop. If the results are comparable, that will be an amazing achievement in itself. Interesting to see what your most distant daytime MW groundwave signal that can be obtained with both antennas.

Regards,

Todd


KGB 760

Mike Sanburn
 

Call change is logged on my little Sangean DT160. Heard spot for San Diego Honda dealers and promo for Mark Larson Show. 0800 PDT top of hour call letter ID read very quickly then into CBS news. Former KFMB for decades. 
Mike Sanburn
Lakewood CA 


Re: Gary's New 6" FSL Design

Gary DeBock
 

<<<   Hi Gary,
Your new 6 inch FSL is a step towards higher gain in a relatively small package. I look forward to a YouTube review.   >>>

Thanks Todd,

The master plan behind this new 6" FSL design was to use all the high-Q components discovered in the compact, airport-friendly FSL experimentation and combine them with powerful ferrite gain. The performance results do seem worthy of the effort, and I'll try to post a demo video soon.

<<<   Regarding 1162/46 Litz wire used in the 6" FSL, what is the cheapest source of supply that you have found so far?   >>>  

I always use the 1162/46 Litz wire from the eBay seller "Mkmak222," which runs US$1 per foot. Of course this is pretty expensive for the average experimenter, who will need about 32 feet to make a Medium Wave FSL, not to mention the 60-watt soldering iron required for proper installation. There are many cheaper varieties of Litz wire available such as 660/46 and 330/46, and unless a DXer absolutely needs the highest sensitivity in the most compact antenna (such as for overseas air travel, etc.), the cheaper Litz wire is OK in most applications.

<<<   On AU eBay, 1162/46 Litz wire is quite expensive. Assuming 19 turns in your design, when I build one, there should be at least 1 or 2 extra turns to allow ferrite rod permeability variation.
21(6 x 3.1416) = 396 inches or 33 feet of wire.    >>>

Yes, 33 feet would probably be the minimum safe length of 1162/46 Litz wire to use for an MW coil if you are not sure how all the manufacturing differences will shake out in the final tuning range. It's no fun to wind an MW coil, and then find out that it won't tune down to 530 kHz because your variable cap doesn't have as much capacitance as your previous model.

<<<   The cheapest 1162/46 Litz wire on AU eBay is US $88 for 60 feet. No smaller minimum 33 feet length is available.
   >>>

Yes, this type of Litz wire should be reserved for fanatical DXer projects, in which you tweak a tiny antenna into an outrageously sensitive, ridiculously effective gain monster for the tiny size. I've posted a 3" Baby FSL video to show this effect. But the expense of this Litz wire is steep, and probably unnecessary unless you absolutely must have a tiny little DXing "firecracker."

<<<   With tank coil Q > 500, the bandwidth will average only 2 KHz or less. The audio fidelity will be compromised as a result. Resonant tuning peak will also be sharper. Higher Q = narrower RF signal bandwidth, degraded high frequency audio response, but high signal strength when tuned to resonance.   >>>

All certainly true, Todd. The highest "Q" FSL antennas have the narrowest bandwidth, which causes some loss of high frequency audio from a DX station. This compromised audio can be somewhat improved by audio processing software, but a razor-sharp-tuning FSL antenna will always clip off some high frequency audio when its frequency matches that of a weak DX station on an Ultralight radio. It's part of the game, and you learn to use the audio processing software to compensate.

<<<   During the process of testing various early design FSLs, what did you find by using lower resistance wires regarding varying degrees of S/N readability, bandwidth, and audio quality? For an air core loop with 1000 Q, the audio will be quite muffled at 531 KHz.   >>>

The early FSL's had pretty low Q, wimpy sensitivity from their smaller Litz wire and relatively good audio from the Ultralight radios. The latest high Q gain monsters sacrifice some audio quality in an all-out pursuit of the highest sensitivity, and their 1162/46 Litz wire will drain your bank account. But all is forgiven when an S9+ Kiwi DX signal thunders across the ocean at over 7,000 miles when you are on an ocean side cliff-- especially one which rarely shows up at all on a flat ocean beach.

Gary



 

 

    

         
   


Re: Soldering Litz Wire Method

kevin asato
 

Thanks for saying what I was thinking!

Isn't this just a variation to the solder pot?
73,
kevin
kc6pob

On Fri, Jul 3, 2020 at 6:52 PM Paul Blundell <tanger32au@...> wrote:
Great post and interesting comment on the wife finding the spoon, I think some might prefer we were doing drugs and not playing radios.

On Sat, 4 Jul 2020, 2:26 a.m. lamontcranston17, <nojunk@...> wrote:
Just a comment about soldering litz wire after seeing Gary's comment
about a 65 watt iron..

  I have a had success using a stainless steel spoon set on a burner of
the stove.

You will probably need to bend it or rest it on something to get it ti
set level on the burner.

I set the burner on high and melt a  enough solder in the spoon that I
can dip the end of the Litz wire into it at an angle.

That temp setting may me able to be reduced, but it needs to be hot.
Experiment.

I make sure to use rosin flux on the Litz wire. It is basically a small
solder pot that does a good job.

It is a little tricky because your fingers can only stay near the hot
burner so long!

Take the spoon when the wife's not looking and do not return it.

If she finds the spoon with a burned rosin stain, she will question
whether you are shooting drugs.


                          Mikek


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus





Re: Soldering Litz Wire Method

Paul Blundell
 

Great post and interesting comment on the wife finding the spoon, I think some might prefer we were doing drugs and not playing radios.


On Sat, 4 Jul 2020, 2:26 a.m. lamontcranston17, <nojunk@...> wrote:
Just a comment about soldering litz wire after seeing Gary's comment
about a 65 watt iron..

  I have a had success using a stainless steel spoon set on a burner of
the stove.

You will probably need to bend it or rest it on something to get it ti
set level on the burner.

I set the burner on high and melt a  enough solder in the spoon that I
can dip the end of the Litz wire into it at an angle.

That temp setting may me able to be reduced, but it needs to be hot.
Experiment.

I make sure to use rosin flux on the Litz wire. It is basically a small
solder pot that does a good job.

It is a little tricky because your fingers can only stay near the hot
burner so long!

Take the spoon when the wife's not looking and do not return it.

If she finds the spoon with a burned rosin stain, she will question
whether you are shooting drugs.


                          Mikek


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus





Soldering Litz Wire Method

lamontcranston17
 

Just a comment about soldering litz wire after seeing Gary's comment
about a 65 watt iron..

 I have a had success using a stainless steel spoon set on a burner of
the stove.

You will probably need to bend it or rest it on something to get it ti
set level on the burner.

I set the burner on high and melt a  enough solder in the spoon that I
can dip the end of the Litz wire into it at an angle.

That temp setting may me able to be reduced, but it needs to be hot.
Experiment.

I make sure to use rosin flux on the Litz wire. It is basically a small
solder pot that does a good job.

It is a little tricky because your fingers can only stay near the hot
burner so long!

Take the spoon when the wife's not looking and do not return it.

If she finds the spoon with a burned rosin stain, she will question
whether you are shooting drugs.


                         Mikek


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Re: Long Term DX Project - 27/06/2020

Dan Merta
 

Ah ok. Iv'e been hearing 4QL from Longreach coming in at night lately. I'll listen in during the day. 


Long Term DX Project - 1/07/2020

Paul Blundell
 

Date: 1/07/2020
Time: 19:30
Location: Home, Launceston Tasmania
Notes: Early evening session at home.
 
 
Freq
Callsign
Logged
531
3GG
GOOD
549
2CR
GOOD
594
3WV
EXCELLENT
621
3RN
EXCELLENT
774
3LO
EXCELLENT
1053
2CA
AVERAGE
1179
3RPH
POOR
1341
HPON GEELONG
GOOD
1422
HPON MELBOURNE
GOOD
1503
3KND
AVERAGE
 
 


Re: Gary's New 6" FSL Design

Gary DeBock
 

On Thu, Jul 2, 2020 at 08:09 AM, Gord Seifert wrote:
Hi guys. I am mainly a lurker here but this post forces me to ask a question. If the Q of the 1162 strand Litz is bordering on too high, why not use 660? The price of 100 ft. of 660 is about the same as 60 ft. of the 1162. The description of the 660 lists ridiculous Q numbers, even with about half the strands, although I have no idea how that would directly compare to the 1162 since he doesn't mention testing Q with 1162. Nor do I know how they would compare when used to create an FSL.
Hi Gord (and Todd),

Todd, thanks for your interest and questions about the new 6" FSL design, which I plan to answer in detail within a day or so.

Gord, 660/46 Litz wire was actually used in all of the most sensitive medium wave FSL antenna designs from 2011 until 2014, when the new 1162/46 Litz wire first became available. As such, all of the DXpedition FSL's (and long range AM-DX results) from 2011-2014 were based on this Litz wire.

After the new 1162/46 Litz wire became available in 2014 it was substituted for the 660/46 Litz wire in a few FSL test models here, and direct A/B signal test comparisons were made on weak signals received by otherwise identical FSL models. The 1162/46 Litz wire models always significantly outperformed the 660/46 models in weak signal reception, to the extent that 660/46 Litz wire was never again used in any of my new FSL designs. The new 1162/46 Litz wire has been one of deciding factors in the success of the new "Frequent Flyer" overseas DXpedition FSL models, which have received AM-DX at over 8,000 miles in places like Hawaii and the Cook Islands.

Of course the high cost of 1162/46 Litz wire is a drawback for many experimenters, not to mention the 60-watt soldering iron required for proper installation. 660/46 Litz wire will certainly be more sensitive than 330/46 Litz wire or something smaller, and unless a fanatical DXer needs the best possible reception in the smallest possible FSL (like for overseas traveling), 660/46 Litz wire is acceptable for most hobbyists. I have never run "Q" tests to compare the performance difference between 1162/46 and 660/46 Litz wire, but the audio signal reception difference between the two was clear enough to make a permanent believer out of this FSL fanatic. If you have any doubts about its performance, feel free to watch the 3" Baby FSL demo video, where it boosts an S3 fringe signal into an S9+ overload  https://www.youtube.com/watch?v=JZtYli09mTg&t
          
Gary DeBock (in Puyallup, WA, USA)

  


Re: Gary's New 6" FSL Design

Gord Seifert
 


   Hi guys. I am mainly a lurker here but this post forces me to ask a question. If the Q of the 1162 strand Litz is bordering on too high, why not use 660? The price of 100 ft. of 660 is about the same as 60 ft. of the 1162. The description of the 660 lists ridiculous Q numbers, even with about half the strands, although I have no idea how that would directly compare to the 1162 since he doesn't mention testing Q with 1162. Nor do I know how they would compare when used to create an FSL.

https://www.ebay.com/itm/Litz-wire-660-46-for-Crystal-Radio-coil-Amateur-Single-layer-insulation-60/160428065987?hash=item255a4204c3:g:CM0AAOSw5VFWMEL1&redirect=mobile

   Regards,
   Gord 
 


Gary's New 6" FSL Design

Todd
 

Hi Gary,

Your new 6 inch FSL is a step towards higher gain in a relatively small package. I look forward to a YouTube review.

Regarding 1162/46 Litz wire used in the 6" FSL, what is the cheapest source of supply that you have found so far?

On AU eBay, 1162/46 Litz wire is quite expensive. Assuming 19 turns in your design, when I build one, there should be at least 1 or 2 extra turns to allow ferrite rod permeability variation.

21(6 x 3.1416) = 396 inches or 33 feet of wire.

The cheapest 1162/46 Litz wire on AU eBay is US $88 for 60 feet. No smaller minimum 33 feet length is available.

With tank coil Q > 500, the bandwidth will average only 2 KHz or less. The audio fidelity will be compromised as a result. Resonant tuning peak will also be sharper. Higher Q = narrower RF signal bandwidth, degraded high frequency audio response, but high signal strength when tuned to resonance.

During the process of testing various early design FSLs, what did you find by using lower resistance wires regarding varying degrees of S/N readability, bandwidth, and audio quality? For an air core loop with 1000 Q, the audio will be quite muffled at 531 KHz.

Regards,

Todd

https://www.ebay.com.au/itm/Litz-wire-1162-46-for-Amateur-Crystal-Radio-coil-Single-layer-insulation-60/153541573281?hash=item23bfca7aa1:g:aT0AAOxyTjNSdFlQ


Re: Long Term DX Project - 27/06/2020

Paul Blundell
 

Nope, 7SD still going.


On Wed, 1 Jul 2020, 9:44 p.m. Dan Merta, <dnmerta0@...> wrote:
2CA 1053 kHz has been coming into Melb well too lately. 
I take it 540 kHz 7SD has been shut down then. 
Regards. Dan. 


Re: Demo of my newly constructed 3.5" FSL

Paul Blundell
 

That is a very good idea, I will try the same with mine.


On Wed, 1 Jul 2020, 7:45 p.m. Gary DeBock via groups.io, <D1028Gary=aol.com@groups.io> wrote:
Paul,

The solution is a "rubber locking tab," which is precut on one side to fit around the curved PVC fitting, and cut flat on the other side to fit up against the rubber plumbing coupler. The rubber locking tab is then superglued to both of these surfaces, with the glue around the plumbing coupler allowed to contact the ends of a couple of ferrite rods. This glued-on rubber locking tab solves both problems.

I have attached a photo of a "rubber locking tab" on a new 6 inch FSL antenna, which is an all-new design incorporating all of the recent high-Q improvements with additional ferrite gain. These powerful new models provide sensitivity very close to the original 15" Monster FSL's-- without the $1K price.

Gary DeBock (in Puyallup, WA, USA)


Re: Demo of my newly constructed 3.5" FSL

Chuck
 

On Tue, Jun 30, 2020 at 10:26 PM, Gary DeBock wrote:
Congratulations again on your success, and good luck tracking down lots of DX!
Thank you Gary! It's a great way to practice the hobby anywhere.
Best to you.


Re: Long Term DX Project - 27/06/2020

Dan Merta
 

2CA 1053 kHz has been coming into Melb well too lately. 
I take it 540 kHz 7SD has been shut down then. 
Regards. Dan. 


Re: Demo of my newly constructed 3.5" FSL

Gary DeBock
 

Paul,

The solution is a "rubber locking tab," which is precut on one side to fit around the curved PVC fitting, and cut flat on the other side to fit up against the rubber plumbing coupler. The rubber locking tab is then superglued to both of these surfaces, with the glue around the plumbing coupler allowed to contact the ends of a couple of ferrite rods. This glued-on rubber locking tab solves both problems.

I have attached a photo of a "rubber locking tab" on a new 6 inch FSL antenna, which is an all-new design incorporating all of the recent high-Q improvements with additional ferrite gain. These powerful new models provide sensitivity very close to the original 15" Monster FSL's-- without the $1K price.

Gary DeBock (in Puyallup, WA, USA)


Re: Demo of my newly constructed 3.5" FSL

Paul Blundell
 

Thanks Get, I have had both those issues. What are the fixes?


On Wed, 1 Jul 2020, 3:26 p.m. Gary DeBock via groups.io, <D1028Gary=aol.com@groups.io> wrote:
<<<   Here's a quick demo of my newly constructed 3.5" FSL. Reception is of the clear channel 50K watt station CFZM in Toronto under poor conditions.
FSL Antenna Demo with Tecsun PL-660This FSL uses 140mm x 8mm rods from a different source since sufficient quantity weren't available from the eBay seller.
https://www.rf-microwave.com/en/ferrite-rods/171/   >>>

Awesome job, Chuck. You obviously aced the 3.5" FSL construction project, and I'm honored to have provided the plans!

By the way, that size of FSL antenna is ideal as a travelling DX companion, either on the road, or as a TSA-friendly overseas DXing antenna (once the Pandemic is over). Craig Barnes from Colorado has used a similar model to track down tons of TP-DX on ocean beaches here in Washington state, along with his PL-380.

There have been a couple of minor improvements made in that model since the construction plans were published, which I'll share with anyone interested (related to stopping unwanted ferrite sleeve rotation, and stopping the ferrite rods from sliding horizontally back and forth during travel).

Congratulations again on your success, and good luck tracking down lots of DX!

73, Gary DeBock (in Puyallup, WA, USA)


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