Date   

SRF antenna transplant comments

sloshatron <wa1gwh@...>
 

Thank you for the reply, Gary. It's nice to know that only matching
up the inductance is close enough!

Thank you for the comment and question, Guy. My understanding is
that despite their being two separate coils on the stock SRF
loopstick and despite the bigger coil being tapped the entire unit
works as a single untapped inductor in the circuit. The tap does not
seem important (it may have been used in some other model?) and the
second smaller coil is slid along the bar to vary the inductance of
the whole loopstick unit for alignment purposes.

So with regard to a possible spider web transplant, I was thinking of
a single continuous wind with just a touch more total inductance.
Alignment would be accomplished by removing/adding turns or partial
turns. Since this could not be done with the radio running and while
listening to a test signal, I'm wondering if measuring the audio
output with a meter (as shown in the service manual) each trial as
turns are removed/added and the radio repeatedly turned on and off
for the procedure might work.

I'm just kind of dreaming about this. The Rap N Tap discussion group
of the Xtal Set Society has kicked around the idea that ferrite can
vary in its quality, even from the same supplier. It is indeed
easier to use, especially for this application, but I only have a big
old ferrite bar of unknown material and quality on hand. I wound on
enough #20 PVC coated hookup wire to get me into the top half of the
MW band and compared it to a 4 1/2 inch air core basket weave
solenoid coil of #21 solid using the same variable capacitor for both
tests. This was a booster bar antenna setup like Gil Stacy's idea,
my SRF was operated stock. The result was that the air core solenoid
was way better than the ferrite bar. Use of the air core coil gave
substantial signal level increase.

This was not a fair test, however, because the winding on the ferrite
bar is substantially non-optimum. I covers too much of the bar and
was not separated an eighth inch or so from the bar (based on info
from our guru, Ben Tongue).

I am planning to do a better winding on the ferrite bar when I figure
out how and get around to it. Based on my scan of Ben's article, #30
wire centered with turns spaced at least one wire diameter and about
an eighth inch off the bar should be a better configuration for this
type of inductor.

Ben's article can be found at:

http://www.bentongue.com/xtalset/29MxQFL/29MxQFL.html

Whether the performance differences he indicates are observable with
amplified radios like the SRFs remains to be seen.

Garry
near Syracuse, NY


20 Inch Loopstick Overloads SRF-39FP

Gary DeBock
 

Hello Guys,
 
     Apparently not even the crunch-resistant CXA1129 chip can handle the mega-RF from a 20 inch loopstick.
 
     Working OK until the 1400 kHz trimmer was peaked, the huge RF onslaught finally did in the CXA1129 "radio on a chip," and the "birdies" started to fly.  This is not the first time that the mega-loopsticks have overloaded the CXA1129;  but some of the IC chips are apparently more crunch-proof than others, and the 14-inch loopstick model has never had any problems.  Two of the four 7-inch models had minor birdies, but the other two were essentially free of spurs.  If you are considering a loopstick transplant, it's kind of an uncertainty as to whether your CXA1129 can handle the extreme RF levels.  If not, you can always reconnect it in stock form.
 
     The 20-inch loopstick may need to give its mega-RF to a different SRF-39FP, or if not possible, maybe a DT-200VX or E100.  Sooner or later, it should find a nice home.
 
                                                                                                        73,  Gary    




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Re: Calling John Bryant / Firsts and distance records

Dennis Gibson <wb6tnb@...>
 

How much difference did the tweak make? I have a number of headphones;
the Sennheiser HD 420 sounds the best.

My SRF-59 and 39FP are stock; at some point I'll have Gary work his
magic on them. I do not disassemble electronic equipment. Disaster is
sure to follow.

--- In ultralightdx@yahoogroups.com, Paul Logan <paulloganradio@...>
wrote:

Hi Dennis,

I have two SRF59's one was tweaked by me - as it turns out the tweak
brought radio # 2 up to the level of the other stock one in terms of
sensitivity so I may have got a "dud".

However I did get the 2nd radio to tune the x- band which the stock
Euro versions don't cover.

All of the TA signals outside the x band were heard completely
barefoot - x band catches were made by placing the radio inside a 4
foot loop.

Great little radio - I'm also very taken with its audio - I often
hear WLAA 1680 and the Mexican music sounds superb.


Re: Argentina on 1620

Dennis Gibson <wb6tnb@...>
 

You know what they say; two people divided by a common language.

--- In ultralightdx@yahoogroups.com, Paul Logan <paulloganradio@...>
wrote:

One of these days I will manage English! that was supposed to read "
with a two foot loop"


Re: Argentina on 1620

Paul Logan
 

Hi Huelbe,

at 0233 UTC it is playing the Beatles "Please Please Me" OM dj, weak.

huelbe_garcia@... wrote:
Hi Paul,
 
can you describe what kind of programming you heard? If we can confirm that, it's a nice DX!
 
I live next to Argetina (south Brazil) and there is an station on 1620 really strong. I learnt it relays an FM and programming and is basically popular rock music from 70s to 90s. It is called "Universo".
 
This station is located in Mar Del Plata, Argentina.
 
Huelbe
Porto Alegre, Brazil
 
 
----- Original Message -----
From: Paul Logan
Sent: Saturday, April 05, 2008 11:00 PM
Subject: [ultralightdx] Argentina on 1620

Hey All,

which Argentine station on 1620 really "gets out" weak on the srf59 with a one two foot loop.


Paul Logan,
Lisnaskea, N. Ireland

Listening Homepage: http://geocities.com/yogi540/
Photos: http://www.flickr.com/photos/radiofotos/
Video: http://www.youtube.com/user/yogi540
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Re: fanatical mega-loopstick question

Guy Atkins
 

Hi Garry,

I had been thinking about spider coils also for an ultralight. How large of a coil form do you think would be needed to compete with a hot rodded ferrite loop? Also, do you envision concentric coils on the form separated by a distance or one continuous coil with tap points as needed?

Guy Atkins
Puyallup, WA USA
www.perseus-sdr.blogspot.com

Sent via BlackBerry from T-Mobile

-----Original Message-----
From: "sloshatron" <wa1gwh@twcny.rr.com>

Date: Sat, 05 Apr 2008 22:58:16
To:ultralightdx@yahoogroups.com
Subject: [ultralightdx] fanatical mega-loopstick question


Hi Gary;

When you measure the recycled coils on the LCR meter, are you
checking only the L or are you somehow taking into account any C
differences between the original and tranplant coils (either on or
off the ferrite bars)? This would be the distributed capacity of the
coils.

If this is working with just L measurements that would be great and
much easier for folks to duplicate.

Also, I'm still thinking about air core coils (small loop antenna
style) to replace the original ferrite loopstick. I realized that if
spider web construction was used it would be much easier to take off
turns and portions of turns and if necessary to add them back on if
the best spot was missed in the iterative alignment process. A
spider web coil form could be cut out of plastic with one spoke
extending way out to mount the form to the radio in the same way as
your ruler idea.

TNX,

Garry Nichols
near Syracuse, NY


Re: Argentina on 1620

huelbe_garcia@...
 

Hi Paul,
 
can you describe what kind of programming you heard? If we can confirm that, it's a nice DX!
 
I live next to Argetina (south Brazil) and there is an station on 1620 really strong. I learnt it relays an FM and programming and is basically popular rock music from 70s to 90s. It is called "Universo".
 
This station is located in Mar Del Plata, Argentina.
 
Huelbe
Porto Alegre, Brazil
 
 

----- Original Message -----
From: Paul Logan
Sent: Saturday, April 05, 2008 11:00 PM
Subject: [ultralightdx] Argentina on 1620

Hey All,

which Argentine station on 1620 really "gets out" weak on the srf59 with a one two foot loop.


Paul Logan,
Lisnaskea, N. Ireland

Listening Homepage: http://geocities.com/yogi540/
Photos: http://www.flickr.com/photos/radiofotos/
Video: http://www.youtube.com/user/yogi540

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Re: Argentina on 1620

Paul Logan
 

One of these days I will manage English! that was supposed to read " with a two foot loop"

Paul Logan wrote:
Hey All,

which Argentine station on 1620 really "gets out" weak on the srf59 with a one two foot loop.


Paul Logan,
Lisnaskea, N. Ireland



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Argentina on 1620

Paul Logan
 

Hey All,

which Argentine station on 1620 really "gets out" weak on the srf59 with a one two foot loop.


Paul Logan,
Lisnaskea, N. Ireland

Listening Homepage: http://geocities.com/yogi540/
Photos: http://www.flickr.com/photos/radiofotos/
Video: http://www.youtube.com/user/yogi540

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Re: fanatical mega-loopstick question

Gary DeBock
 

Garry and Guy,
 
     All of the mega-loopsticks (7", 14" and 21") have been constructed using an LCR meter to measure inductance only, to ensure that the recycled coils (mostly salvaged from the vintage long ferrite bars) match the  SRF-39 stock coils in inductance.  The alignment procedure, in which the small coil is slid along the ferrite bar to peak a low-band (usually 600 kHz) signal,  optimizes the match between the recycled coils and the SRF-39 circuitry, making it unnecessary to measure capacitance and resistance during the construction process.  As long as the inductances match, and the 600 kHz peak is sharp, the newly recylced coils are perfect for DX reception in the SRF-59.
     As for comparison of the ferrite mega-loopsticks and  spider coils, I'm sorry that I have never experimented with spider coils, or air-core loops.  The ferrite mega-loopsticks seem to be great for DX, relatively cheap, and still quite portable.  The only drawback is that you inevitably make longer and longer ones, as you fanatically strive for the highest sensitivity level.  Eventually you need to face the reality that doorways are only 30" wide.
     Guy, if you wish to make some spider coils and compare them to the mega-loopsticks, you can borrow them at any time (Guy and I live in the same city).  As of today, all of them will still fit through a doorway  :>)
 
                                                                                           73,  Gary
    
   




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Re: Calling John Bryant / Firsts and distance records

Paul Logan
 

Hi Dennis,

I have two SRF59's one was tweaked by me - as it turns out the tweak brought radio # 2 up to the level of the other stock one in terms of sensitivity so I may have got a "dud".

However I did get the 2nd radio to tune the x- band which the stock Euro versions dont cover.

All of the TA signals outside the x band were heard completely barefoot -  x band catches were made by placing the radio inside a 4 foot loop.

Great little radio - Im also very taken with its audio - I often hear WLAA 1680 and the Mexican music sounds superb.

Dennis Gibson wrote:
Paul - is your SRF-59 stock (not tweaked for best performance)? Are
your non expanded band logs barefoot or with the loop?

73



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Re: Calling John Bryant / Firsts and distance records

bjohnorcas@...
 

THANKS, PAUL....

I have no idea what happened to your first note. I'll be doinm a List
update when I get back to Stillwater in a few days.

John B.

Hi John,

I mailed you some time back regarding firsts and distance records, I guess
you didn't receive it so here goes again:

I have worked out that my first UL loggings from North America were as
follows.

WWZN Boston MA, USA, 1510, 2-10-08, Sony SRF-59, Barefoot
(50 kw night 2941 miles / 4732 km)
CKEC New Glasgow NS, Canada, 1320, 2-10-08, Sony SRF-59, Barefoot
(25 kw night 2468 miles / 3972 km)

As for Unlimited class first one was

WTNI Biloxi, MS, 1640, 2-10-08, Sony SRF-59, Unlimited class
(1kw night 4214 miles / 6782 km)

These will also be of interest - looks like a new record for 50 kw:
WWVA, Wheeling WV, 1170, 4-4-08, Sony SRF-59 Barefoot
3425 miles / 5512 km.

Same for 10kw:
CBI, Sydney NS, 1140, 3-24-08,Sony SRF-59 Barefoot, 2351 miles / 3783 km

Nice 5 kw catch:
WLAM, lewiston, ME, 1470, 4-3-08, SRF-59 Barefoot, 2831 miles / 4557 km

New 1 kw record? (this one does run 1kw nights - right?)
CKNB, Campbellton, NB, 950, 4-4-08, SRF-59 Barefoot, 2530 miles / 4072 km

I also have a slew of 1 kw x band loggings unlimited class mostly using a
4 foot loop with the SRF59.

1630 WRDW Augusta GA 1 05:35 30/03/2008 3788 miles 6096
km
1650 WHKT Portsmouth VA 1 05:32 30/03/2008 3399 5470
1670 WVVM Dry Branch, GA 1 05:37 30/03/2008 3887 6256
1680 WLAA Winter Garden, FL 1 05:40 30/03/2008 4019 6468
1620 WDHP Saint Croix USVI 1 06:10 02/04/2008 3931 6326
1700 WEUP Huntsville, AL 1 05:45 02/04/2008 3909 6292
1660 WFNA Charlotte NC 1 05:50 02/04/2008 3657 5885

I am fairly sure that I have had KVNS on 1700 Barefoot this would be 4794
miles but not willing to claim with no id - the station heard had oldies
and KVNS is usually dominant here on this freq - amazing when you think
they run 880 watts at night.

Hope these logs are of interest.

have you thought of a flea class for reception of 1 watters - I have one
at about 270 miles!.

regards for now

Paul Logan
Lisnaskea, N. Ireland.


bjohnorcas@rockisland.com wrote: Paul,

You might check the World Records at various transmitter powers. You
might
be setting records for 50 kW stations, for instance. In any case, a
great
set of loggings!

John Bryant








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My first image on the SRF-59

John Cereghin <jcereghin@...>
 


fanatical mega-loopstick question

sloshatron <wa1gwh@...>
 

Hi Gary;

When you measure the recycled coils on the LCR meter, are you
checking only the L or are you somehow taking into account any C
differences between the original and tranplant coils (either on or
off the ferrite bars)? This would be the distributed capacity of the
coils.

If this is working with just L measurements that would be great and
much easier for folks to duplicate.

Also, I'm still thinking about air core coils (small loop antenna
style) to replace the original ferrite loopstick. I realized that if
spider web construction was used it would be much easier to take off
turns and portions of turns and if necessary to add them back on if
the best spot was missed in the iterative alignment process. A
spider web coil form could be cut out of plastic with one spoke
extending way out to mount the form to the radio in the same way as
your ruler idea.

TNX,

Garry Nichols
near Syracuse, NY


Re: Calling John Bryant / Firsts and distance records

Dennis Gibson <wb6tnb@...>
 

Paul - is your SRF-59 stock (not tweaked for best performance)? Are
your non expanded band logs barefoot or with the loop?

73

--- In ultralightdx@yahoogroups.com, Paul Logan <paulloganradio@...>
wrote:

Hi John,

I mailed you some time back regarding firsts and distance records, I
guess you didn't receive it so here goes again:

I have worked out that my first UL loggings from North America were
as follows.

WWZN Boston MA, USA, 1510, 2-10-08, Sony SRF-59, Barefoot
(50 kw night 2941 miles / 4732 km)
CKEC New Glasgow NS, Canada, 1320, 2-10-08, Sony SRF-59, Barefoot
(25 kw night 2468 miles / 3972 km)

As for Unlimited class first one was

WTNI Biloxi, MS, 1640, 2-10-08, Sony SRF-59, Unlimited class
(1kw night 4214 miles / 6782 km)

These will also be of interest - looks like a new record for 50 kw:
WWVA, Wheeling WV, 1170, 4-4-08, Sony SRF-59 Barefoot
3425 miles / 5512 km.

Same for 10kw:
CBI, Sydney NS, 1140, 3-24-08,Sony SRF-59 Barefoot, 2351 miles / 3783 km

Nice 5 kw catch:
WLAM, lewiston, ME, 1470, 4-3-08, SRF-59 Barefoot, 2831 miles / 4557 km

New 1 kw record? (this one does run 1kw nights - right?)
CKNB, Campbellton, NB, 950, 4-4-08, SRF-59 Barefoot, 2530 miles /
4072 km

I also have a slew of 1 kw x band loggings unlimited class mostly
using a 4 foot loop with the SRF59.

1630 WRDW Augusta GA 1 05:35 30/03/2008 3788 miles
6096 km
1650 WHKT Portsmouth VA 1 05:32 30/03/2008 3399 5470
1670 WVVM Dry Branch, GA 1 05:37 30/03/2008 3887 6256
1680 WLAA Winter Garden, FL 1 05:40 30/03/2008 4019 6468
1620 WDHP Saint Croix USVI 1 06:10 02/04/2008 3931
6326
1700 WEUP Huntsville, AL 1 05:45 02/04/2008 3909 6292
1660 WFNA Charlotte NC 1 05:50 02/04/2008 3657 5885

I am fairly sure that I have had KVNS on 1700 Barefoot this would be
4794 miles but not willing to claim with no id - the station heard had
oldies and KVNS is usually dominant here on this freq - amazing when
you think they run 880 watts at night.

Hope these logs are of interest.

have you thought of a flea class for reception of 1 watters - I
have one at about 270 miles!.

regards for now

Paul Logan
Lisnaskea, N. Ireland.


Calling John Bryant / Firsts and distance records

Paul Logan
 

Hi John,

I mailed you some time back regarding firsts and distance records, I guess you didn't receive it so here goes again:

I have worked out that my first UL loggings from North America were as follows.

WWZN Boston MA, USA, 1510, 2-10-08, Sony SRF-59, Barefoot
(50 kw night 2941 miles / 4732 km)
CKEC New Glasgow NS, Canada, 1320, 2-10-08, Sony SRF-59, Barefoot
(25 kw night 2468 miles / 3972 km)

As for Unlimited class first one was

WTNI Biloxi, MS, 1640, 2-10-08, Sony SRF-59, Unlimited class
(1kw night 4214 miles / 6782 km)

These will also be of interest - looks like a new record for 50 kw:
WWVA, Wheeling WV, 1170, 4-4-08, Sony SRF-59 Barefoot
3425 miles / 5512 km.

Same for 10kw:
CBI, Sydney NS, 1140, 3-24-08,Sony SRF-59 Barefoot, 2351 miles / 3783 km

Nice 5 kw catch:
WLAM, lewiston, ME, 1470, 4-3-08, SRF-59 Barefoot, 2831 miles / 4557 km

New 1 kw record? (this one does run 1kw nights - right?)
CKNB, Campbellton, NB, 950, 4-4-08, SRF-59 Barefoot, 2530 miles / 4072 km

 I also have a slew of 1 kw x band loggings unlimited class mostly using a 4 foot loop with the SRF59.

1630    WRDW Augusta GA     1    05:35    30/03/2008    3788 miles    6096 km
1650    WHKT Portsmouth VA      1    05:32    30/03/2008    3399    5470
1670    WVVM Dry Branch, GA    1    05:37    30/03/2008    3887    6256
1680    WLAA Winter Garden, FL  1    05:40    30/03/2008    4019    6468
1620    WDHP Saint Croix USVI    1    06:10    02/04/2008    3931    6326
1700    WEUP Huntsville, AL    1    05:45    02/04/2008    3909    6292
1660    WFNA Charlotte NC    1    05:50    02/04/2008    3657    5885

I am fairly sure that I have had KVNS on 1700 Barefoot this would be 4794 miles but not willing to claim with no id - the station heard had oldies and KVNS is usually dominant here on this freq - amazing when you think they run 880 watts at night.

Hope these logs are of interest.

have you thought of a flea class for reception of 1 watters -  I have one at about 270 miles!.

regards for now

Paul Logan
Lisnaskea, N. Ireland.


bjohnorcas@... wrote:
Paul,

You might check the World Records at various transmitter powers. You might
be setting records for 50 kW stations, for instance. In any case, a great
set of loggings!

John Bryant



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20.25" Loopstick Successfully Tansplanted into SRF-39FP

Gary DeBock
 

Hello Guys,
 
     The fanatical mega-loopstick experimentation with the SRF-39FP has reached a new level (perhaps along with the eccentricity of the experimentor).
 
     Using two 7" and one 6.25" ferrite bars tightly taped together (then reinforced by thick rubber hose), a monster 20.25" ferrite bar was created, and an LCR meter was used to precisely adjust recycled coils to match the inductances on the stock 1.75" ferrite midget bar.  After full alignment, the resulting DX monster smoked a fully-aligned ICF-2010 on all frequencies in sensitivity, providing solid copy of signals at the 2010's noise level.  A fully-aligned ICF-S5W tried but failed to compete on the lower frequencies, then got smoked on the upper frequencies.
 
     Being fully aware that this experimentation has gone well past the point of reason, I think it's time to quit for a while, before the loopsticks fail to fit through a standard doorway.  A general article describing these experiments should be finished for dxer.ca shortly, but if any tinkerer desires specific instructions on how to create one of these DX monsters, please contact me, and specify the loopstick size planned (7", 14" or 20"). It is suggested that multiple SRF-39FP's be ordered off of eBay, if you have a risk of becoming a sensitivity fanatic (like yours truly).
 
                                                                              73,  Gary      




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Re: Off topic balun question

Paul Logan
 

Hi John,

Im familiar with your excellent articles on balun fabrication and in fact have been using them as a reference for ages.

I was just wondering what cores are used in commercial rx baluns which claim to cover long wave up through HF.

Any ideas anyone?.

bjohnorcas@... wrote:
Paul,

I'm outta town for the weekend and away from references. However, from
memory, there really isn't one formulation of ferrite that will work at
OPTIMALLY at Longwave up through 30 MHz. Generally, Bill Bowers and I shot
for really good performance from 5 MHz. down. The problem tends to be at
the lower frequencies, where performance can drop off like it was shot. My
impression is that upper frequency performance is much more forgiving.

I believe that there are two impedance matcher articles on dxing.info. Be
sure that you are reading the latter one, if you only read one.

John B.,



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Re: Loggings for 4/4/08

bjohnorcas@...
 

Paul,

You might check the World Records at various transmitter powers. You might
be setting records for 50 kW stations, for instance. In any case, a great
set of loggings!

John Bryant


Hi all,

a few TA's noted here on the SRF59 barefoot this morning -

850 WEEI
920 CJCH
940 CINW
950 CKNB
1010 CFRB
1010 WINS
1130 WBBR
1170 WWVA

When coupled to a 4 and 2 foot loop around dawn these and others were
pretty easy copy.

regards



Paul Logan,
Lisnaskea, N. Ireland

Listening Homepage: http://geocities.com/yogi540/
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Video: http://www.youtube.com/user/yogi540
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Re: Off topic balun question

bjohnorcas@...
 

Paul,

I'm outta town for the weekend and away from references. However, from
memory, there really isn't one formulation of ferrite that will work at
OPTIMALLY at Longwave up through 30 MHz. Generally, Bill Bowers and I shot
for really good performance from 5 MHz. down. The problem tends to be at
the lower frequencies, where performance can drop off like it was shot. My
impression is that upper frequency performance is much more forgiving.

I believe that there are two impedance matcher articles on dxing.info. Be
sure that you are reading the latter one, if you only read one.

John B.,



Hi Paul:


Our own John Bryant wrote the book on these! Look to
www.dxing.info/equipment/impedance_matching_bryant.doc and
www.dxing.info/equipment/impedance_transformer_bryant2.doc
for the scoop on baluns

Kevin S.
Bainbridge Island, WA



Hi all,

I know this is off topic but was wondering can anyone suggest a suitable
ferrite core for general listening from long wave up to 30 mhz - does
such
a core exist?.

I found a T 200 - 2 in my junk box but when I worked out the turns
needed
to cover 1 - 30 mhz it was something crazy. Any suggestions for
something
useful for this one?.

regards




Paul Logan,
Lisnaskea, N. Ireland

Listening Homepage: http://geocities.com/yogi540/
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