Date   

Adding an Antenna Port to an Ultralight

John H. Bryant <bjohnorcas@...>
 


This started out to be a brief explanation of the subject and an announcement that there is a new photo album showing the steps needed to install an input port for external antennas to one of our ultralights.  That brief note morphed into a rough draft of 2/3 of the article that I'll complete next week for DXer.ca and the clubs. The photo album is the first one in our Photos area at http://ph.groups.yahoo.com/group/ultralightdx/photos

I'm going to do the same mod on the e100 and then complete the article. In the meantime here is the rough of the front part of the article:



For those of us working with the Unlimited Class of receivers, my Nirvana has always been trying to connect these little beasties to external antennas. My primary DXing interest is Trans-Pacific reception and a couple of people have shown it possible to go TP with a Barefoot Ultralight. However, to receive a goodly number of TPs, the assistance of a major external antenna is probably required. Coupling an external antenna to an ultralight can be achieved by inductively by wrapping the lead of the external antenna around the entire radio (very inefficient) or by wrapping the lead around an auxiliary "booster bar" antenna that can even be tuned to boost efficiency. Radio Plus+ even produced a commercial version of the latter called "The Q-Stick." The weakness of all of these strategies, though, is that there is a major antenna (the unshielded lead itself or the ferrite booster bar) right in the shack with you, just waiting to pick up every growl of RF noise from your computers, digital read-outs, etc.

What I really wanted was a method of attaching a shielded 50-ohm coax lead-in DIRECTLY to the ultralight radio, just like the antenna arrangement of a regular communications receiver. Frankly, I did not think that was possible. There were too many problems: impedance mis-match and, if the stock ferrite bar remained in the radio, having it pick up RF interference from the shack environment were the two that worried me the most.

Early on in the my ultralight work, I decided to explore an SRF-39FP, to learn more about the guts of this seminal receiver and particularly to explore the little 1.75" ferrite bar antenna. At the time, I was mostly thinking of REPLACING  the stock bar with something: a larger ferrite bar, air-core loop or, maybe, some sort of direct connection to a long wire, possibly using a ferrite toroid transformer. I disassembled an SRF-39 and mounted the circuit board on a large piece of perf board.  I removed the stock ferrite bar antenna from the circuit board to decode the coils and connections. By that time, others in the ultralight community had discovered that separating the bar antenna from the circuit board often improved signal to noise ratio, so when I was finished with the measurements, I re-mounted the stock bar on a set of screw terminals, just off the edge of the main circuit board. This would allow me to easily remove the stock bar and experiment with other antenna arrangements. 

After mulling things over for a few days, I decided that my first experiment ought to be to try to see just how bad the RF problem was and to eliminate the simplest solution from further consideration. The simplest solution was to place a small coupling coil around the existing bar antenna.  I had no reason to think that this strategy would work very well, since it ignored impedance mismatch issues and left that darn stock bar in place where it could listen to my computer grind out RF interference by the bucket full. I wrapped 13 turns of 28 ga. insulated wire wrap wire around the now-outboard SRF-39 bar and soldered the ends to a chassis-mount BNC jack. I took the radio over to my computer/DXing position and turned it on.  All that I could hear was computer and digital buzzing, along with my two strongest local stations.  Then, I plugged the radio in to my external antennas: a miracle occurred! All and I mean ALL of the buzzing went away, to be replaced with the complete MW band as it should be! To confirm what had happened, I switched to the Wellbrook directional phased array and flipped through the four directions: sure enough, there was a different station mix in each of the four directions.  I went to open frequencies just above/below the band and there was NO RF INTERFERENCE, even on those station-less frequencies. I unplugged the breadboarded SRF-39FP from the external antennas and, instantly, the awful buzz returned. Since the 13 turns of the coupling coil had been determined totally by "what looked right," I decided to remove the turns a few at a time to find the least number that still caused what I now think of as the "swamping effect." I quit at  five turns without noticing any diminution of the effect along the way. 

I do know that impedance mis-match issues are not very serious in a receive only situation, so that may be one aspect to explaining why my little coupling coil worked. Why the stock bar did not continue to "hear" the computer interference, even on an open frequency, when plugged into an external antenna is simply beyond my understanding.

THE SANGEAN DT-200VX
The original breadboarded SRF-39FP eventually went on to become the heart of my table model "National SRF-39" that I've discussed elsewhere. However, my long range goal had really been to couple external antennas directly to two of my digital Ultralights: the Atkins-modified DT-200VX and a stock Eton e100. I started with the DT-200VX, since Guy Atkins had already been inside one and had taken excellent photographs. I examined those and spotted a place to mount an antenna input jack, thankfully rather close to the ferrite bar antenna.

I poured over a 2" thick Mouser catalog trying to find the smallest possible two-conductor jack for the new antenna input port, since most ultralights are almost solid with internal components and open space is at a premium.  I ended up ordering several different plug/jack combinations from Mouser so that I could carefully examine them before making a final selection.  I finally settled on a conventional monaural 2.5 mm mini-jack/plug pair by Kobiconn. (Mouser p/n 171-3304-EX and p/n 16PJ100) In simpler times, these were known as 3/32" phone jacks.

The modification process is really quite simple. I took the back half of the clam shell radio case off, revealing a stack of two circuit boards, interconnected by a set of slip-connect pin/jacks. By the way, three small switch plates that cover switches on the edges of the radio fell out. Not to worry: each switch cover is slightly different in configuration and re-assembly is a snap (literally.) No de-soldering of connecting wires was necessary. I simply raised the upper circuit board off the pin/jacks and rotated it to the right, like opening a book. This exposed both the ferrite bar antenna and the place on the front half of the radio case that needed to be drilled for the new antenna jack. (see photos.) I drilled the side of the case with a Dremel tool, though it should be possible to use an electric drill.... carefully. I installed the new jack, with two wire pig-tails already attached and wrapped the ferrite bar with 8 turns of that same 28 ga. wire wrap wire. I love that stuff, since it is "self stripping" using a hot iron. I then simply cut the wires to length and made staggered solder connections. I did not insulate the joints, since they were staggered and would be in a protected area of the plastic case.

Re-assembly went well and quickly and I soldered together a RG-174-based patch cord (BNC on one end, the 2.5 mm phone jack on the other) and plugged into the Wellbrook Phased Array. It worked like a charm, the first time!




John B.
Stillwater, Oklahoma, USA
Rcvrs: WiNRADiO 313e, Eton e1, NRD-535(kiwa-mods) + Flocka Ultralights
Antennas: 700' NE/SW mini-Bev, Wellbrook Phased Array (pre-production version)


Re: Adding an Antenna Port to an Ultralight

Gary DeBock
 

Great Project, John!
 
     Your success in coupling effective external antennas to the SRF-39FP and DT-200VX ultralights should give you lots of exciting TP-DX at Orcas Island.  Especially with the superb selectivity mod installed by Guy on the DT-200VX, that digital model should really come in handy around September and October.
 
     In February, a couple of DT-200VX units were modified here to receive 6.25" loopstick transplants (which greatly boosted their sensitivity), but the Icom filters provided by Guy have yet to be installed. The units were taken to Grayland on March 13th, where they received very loud TP signals from Japan, but with no selectivity improvements, they had a tricky time dodging the domestic QRM in chasing the weaker TP's.  The modified SRF-39FP (also with a 6.25" transplant) did much better selectivity-wise, splitting off NK-653, China-963 and HLCA-972 without too much trouble.  A lot of time was used trying to receive VOA-1575 on the QRM-troubled DT-200VX (only), when the SRF-39FP possibly could have nailed it.
 
     As Guy and I both discovered, the DT-200VX alignment usually favors either the low end or high end of the band, but not both.  The design is not broadbanded like the SRF-39FP, and two factory units rarely have sensitivity equal in all areas of the band.  My own "solution" was to align one transplant-enabled unit to favor the low end, and one to favor the high end.
 
     Having completed the fanatical loopstick transplant experimentation with the SRF-39FP (and hearing the 20.25" model run wild over classic DX portables in sensitivity), the DT-200VX and ICF-2010 are the next logical candidates for "mega-surgery."  If an Ultralight tinkerer can successfully transplant a 14" or 20" loopstick into the ICF-2010, it may be of some interest to the general AM-DX community (as well as restoring its proper function as a "spotting receiver" for the hot-rodded Ultralights  :>)
 
     Anyway, John, congratulations on your success, and I think both of us will have a lot of fun in the fall.  Maybe both of us can show up at Grayland on the same date, and compare the results of our divergent experimentation.
 
                                                                                            73,  Gary
 
                                                                               73,  Gary 




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Re: Argentina on 1620

huelbe_garcia@...
 

Hi Paul, sorry I was not on-line at that time. However, I can confirm this
kind of music is often heard at 1620 :) (how nice!). --hg

----- Original Message -----
From: Paul Logan
To: ultralightdx@yahoogroups.com
Sent: Saturday, April 05, 2008 11:34 PM
Subject: Re: [ultralightdx] Argentina on 1620


Hi Huelbe,

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


Further comparison of air core vs ferrite bar booster antennas.

sloshatron <wa1gwh@...>
 

A while back I had mentioned that an air core coil had greatly
outperformed a chunky surplus ferrite bar antenna on my SRF-49 when
used as an external booster antenna. I had quickly wound the ferrite
with #20 PVC hookup wire which was centered and occupied just over
half the total length.

I have now rewound the ferrite bar with #24 plastic covered wire
taken from 4 conductor telephone cable. (The insulation looks and
feels like polyethylene, which is great as a dielectric if so.)
There is a single wrap of flexible foamed polyethylene packing sheet
about 1-2 mm thick between the bar and the winding. I started with
the center 1/3 of the bar close-wound with the #24. I then unwrapped
until the inductance was about the same as my air core coil.

I used the same variable capacitor for listening tests on stations at
1010 kHz and 1590 kHz at mid-day for steady sigs. The coils were
axially aligned with the bar on the SRF-49, although the actual axes
were about 2" above the radio bar because the diameter of the air
core is about 4" and I set it on the pine board where the radio is
fastened. I kept both test coil axes at the same height.

Each coil+cap combo was moved away from close to the radio until the
sig strength just started to drop off (as best I could tell by ear
and with AGC on the radio). Four or 5 comparisons were made for each
frequency.

The ferrite bar was much better this time, although not as good as
the air core coil. The air core coil was more noticably better at
1590 than at 1010. In each case, only occasional words were copiable
with the boosters moved way away from the SRF-49. Comfortable 100%
copy was obtained with each booster at both frequencies, although
there was still background hiss. (In fact, I started to listen to a
dumb talk show!)

So, it would appear that an air core coil with a "loop" aspect ratio
(large diameter, short length) may still be an excellent alternative
to a ferrite bar coil. And, it looks like my chunky old ferrite bar
might be a good candidate for an SRF-49 transplant antenna if I
decide to go that route. But I'll have to wind my own coils.

Specs:

Basket wound coil of #21 solid with insulating film:
4.1"D by 1.2"L, 41 turns total about 44.0 feet.

Ferrite bar coil of #24 plastic insulated telephone wire close wound
over poly sheet (1-2 mm):
bar: 123mm L x 31mm W x 11mm thick
coil: 35mm long, centered, about 10.9 feet of wire (a lot less than
the air coil, wire not much smaller but close wound with unknown
insulation touching)

I hope to soon have some photos of my setup.

Garry
near Syracuse, NY


Re: 300 in 30 UL challenge

robert ross
 

At 03:49 PM 4/7/2008, you wrote:

Hi all,

my thirty days are up and what fun it has been - thanks to Rob Ross for
the inspiration.

Not only have new stations been logged but my interest in MW has been
totally reinvigorated.

After 300 I got lazy and didnt put in as much time as I might have liked
- I was also messing around with loops.

The final tally was 316 stations logged barefoot from 55 DXCC countries.

Way to go Paul...I knew you could do it!! Congratulations on obtaining your
goal and then some!! The best part of the whole exercise is that you had
fun....and that's the bottom line of this whole hobby...without the
fun....it's just another job!!

A very impressive list of stuff heard too........much more exotic than my
300 was I'm afraid to say.

Good luck on the next 100 and each 100 after that. I'm stuck at 450...and
with the lessening conditions here lately....may be there for a while. Also
spending more time outside and away from the radio now that the nice
weather is here.....

It will be interesting to see just how many stations can be logged on an
Ultralight over the next few years......who knows??? Is 1,000 stations
possible???? We'll find out in time I guess......

Once again Paul...good work on the 300 in 30 days!

73...ROB.



Robert S. Ross VA3SW
Box 1003, Stn. B.
London, Ontario
CANADA N6A5K1

Antique/Vintage Radio Enthusiast
Amateur Radio Stations VA3SW/VE3JFC

Defy Physics.....Play Table Tennis!! (Ping Pong with an Attitude)
«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»¥«¤»§«¤»¥«


loggings on the SRF-M37V Ultralight

Allen Willie
 

Logged on the SRF-M37V barefoot last couple evenings


April 7/08

22:52 UTC - 954 khz Qatar, QBS; Al Arish w/ arabic music; commentary
by man and woman followed by time tones ; fair

1:50 UTC - 1584 khz Ceuta, R. Ole' w/ portugeuse folk song ; fair w/
fading


April 9/08

2:10 UTC - 999 khz Moldova, Relay of Voice of Russia ;
Grigoriopol ,good

2:25 UTC - 1071 khz Spain, Euskadi Irratia Bilboa w/ spanish fast
paced vocals ; good
( This is the only station i'm hearing so far around 1070 khz since
CBA Moncton, New Brunswick left the air on AM the rest most nights
has been hash )


Allen Willie
VO1-001-SWL
St. John's, Newfoundland
SRF-M37V barefoot


Re: HALF INCH 12.7MM IN DIAMETER FERRITE RODS.

Peter Tankard <peter.tankard@...>
 

HI Gary from peter a very big thnkyou to you I did not know that you can get the old half inch ferrite rods from old radios on Ebay I will get looking right away Best regards from peter tankard.D1028Gary@aol.com wrote:

Hello Peter,

This is Gary DeBock, ferrite rod transplant enthusiast on the
west
coast of the USA. Welcome to the group site, and to the worldwide
Ultralight DX Team.

As you may have suspected, half-inch diameter ferrite rods are no
longer in production, and the only way to obtain them is to purchase
old vintage portable radios from eBay or other sources, and remove
the rods for your projects. This is not an ideal situation, but
currently it is the only possible supply source.

If you need a high-quality half-inch diameter ferrite rod that
is a
full 7.25 inch length, may I suggest the Heathkit GR-17 and GR-24
portables, which occasionally show up on eBay, going for around $25
US. Old Heathkit AM-FM stereo tuners from the 60's (AJ-33, etc.)
also have half inch diameter rods, with lengths around 6.25".

The procurement of 3/8 inch rods is much easier, and an
experimenter in
the USA can usually track down all he needs in short order. Sony
vintage radios (6R-33, TR-6400, ICF-S5W, etc.) all have a 3/8" by
6.25" rod of high quality, and other vintage radios by Panasonic and
Sanyo also have similar rods. These radios (with the exception of
the ICF-S5W) are extremely cheap on
eBay, and go for around $10-20 on average. Most of them are
inoperable, which makes the tinkerer feel a little better when he
takes out the ferrite rod :>)

There will shortly be an article written concerning my 7", 14"
and 20" ferrite-bar transplant experiments in the Sony SRF-39FP
ultralight radio,
which have resulted in ultra-sensitive DX machines. I hope this
detailed article will help those who have interest in this
fascinating experimentation.


73, Gary





**************Planning your summer road trip? Check out AOL Travel
Guides.
(http://travel.aol.com/travel-guide/united-states?ncid=aoltrv00030000000016)
--
Peter Tankard


Re: Calling John Bryant / Firsts and distance records

John H. Bryant <bjohnorcas@...>
 

Great, Paul...

I used the WJCC logging in both the Barefoot and Unlimited Class, since you heard it with and without the loop.  It set a new distance record in both categories for 1,000 watt stations. Congratulations!

John B.


At 02:10 PM 4/8/2008 +0100, you wrote:

Hi John,

look forward to seeing everyones new "bests" - this one may also interest you - the last logged for my 300 in 30 - it was armchair copy with a loop but also there weak on the internal antenna.

1700    WJCC Miami Springs FL    1kw    USA    06:15    04/06/2008 Sony SRF59 Barefoot - 4111 miles / 6616 km

regards for now


Paul Logan,
Lisnaskea, N. Ireland













Re: Calling John Bryant / Firsts and distance records

Paul Logan
 

Hi John,

look forward to seeing everyones new "bests" - this one may also interest you - the last logged for my 300 in 30 - it was armchair copy with a loop but also there weak on the internal antenna.

1700    WJCC Miami Springs FL    1kw    USA    06:15    04/06/2008 Sony SRF59 Barefoot - 4111 miles / 6616 km

regards for now


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: Calling John Bryant / Firsts and distance records

John H. Bryant <bjohnorcas@...>
 

Paul,

I just finished inputting your loggings into the Firsts and Records.... Congratulations!  You pretty much rewrote the Records at most transmitter power levels, for sure.  My records also indicated that the New Brunswick station was 1000 watts at night. And I used the Winter Garden, FL for the 1 kW, since it was your most distant.

I'll publish the list about Thursday and see that you get a copy!

Keep up the great work!
John B.






At 07:53 PM 4/5/2008 +0100, you 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.


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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Re: 300 in 30 UL challenge

John H. Bryant <bjohnorcas@...>
 

Paul!

A huge ATTA BOY!  What an achievement!  I'm really glad to hear that yet another Old Mossback DXer has found fun again at the MW dials..... I can't wait to get to the NW Coast, tho' even there, my totals, Trans-Pacific will pale beside you and Allen Willie.... in country count, for sure.

I really look forward to hearing more about your work with UltraLoops, too.... saw the ones on your website.

Best Regards!

John B.
Stillwater, Oklahoma, USA
Rcvrs: WiNRADiO 313e, Eton e1, NRD-535(kiwa-mods) + Flocka Ultralights
Antennas: 700' NE/SW mini-Bev, Wellbrook Phased Array (pre-production version)


At 08:49 PM 4/7/2008 +0100, you wrote:

Hi all,

my thirty days are up and what fun it has been - thanks to Rob Ross for the inspiration.

Not only have new stations been logged but my interest in MW has been totally reinvigorated.

After 300 I got lazy and didnt put in as much time as I might have liked -  I was also messing around with loops.

The final tally was 316 stations logged barefoot from 55 DXCC countries.

Not bad on a radio that cost me approx $14

I am uploading the logged list to the files section for those interested.

73 ( or in our case 72)  and good listening


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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Hello, John Bryant! A few words on my quick tests.

sloshatron <wa1gwh@...>
 

Well, I did purchase a digital camera a while back but have not
gotten around to putting the software on the PC and figuring it out.
So, for the time being, no pictures are available.

Actually, not much to see! A 4.1" diameter by 1.2" long basket weave
solenoidal air coil vs a surplus ferrite bar with #20 PVC solid
hookup wire wound close over the center half. And a ceramic
insulated variable.

The ferrite bar was picked up at a ham swap table for a few bucks.
It used to be mounted in a plastic housing with a central pivot and
looks to be for some sort of direction finding rig. It was in a box
that appeared to fit it and be the right one. The labeling on the
box said "ANTENNA SUBASSEMBLY AN/ARN-59". There are all kinds of
alpha numeric codes on the label and a bar code (no pun intended).
There is a field that appears to be a date, "02/90". An internet
search led me to believe the unit covered 150-1750 kHz. So this bar
is likely good for MW. It is pretty chuncky at 4.8" long by 1.25"
wide by .42" thick. I'm not especially into ferrite bars, but for a
few bucks I could not resist.

I'm going to see about picking up some 4 conductor telephone cable to
get the #24 insulated wire it is made up of. I will then rewind the
ferrite bar to what I think is a higher Q format with the winding
spaced about 1/8 inch off the bar and the turns occupying a centered
position and taking up much less length of the bar with the smaller
gauge wire and thinner insulation. This will be an easier wind than
space-winding and will give some wire spacing due to the insulation.
Not optimum but quick and easy. Then I'll have another check against
the basket weave air coil. This will again be as an external booster
antenna. I figure that results for a booster antenna will likely
correspond to a transplant.

Not sure where I'm going with this. Just messing around a bit.

By the way, I think that paralleling bars approaches the performance
of thicker bars. I remember reading an article in an ARRL Radio
Amateur's Handbook about paralleling bars to increase sensitivity in
a 160M ferrite bar loop antenna for receiving.

Also, a fairly recent discussion on the Xtal Set Society forum
mentioned bars used end to end. If I remember correctly, results
were best with about a paper's width between the bar ends. But you
are already using bars end to end, John! (Have you looked into
cutting notches into both sides of your doorways yet?)

I'm not sure how paralleled bars stack up (oops!) against end to end
bars in performance. I will dig out the ARRL Handbook article and
report back.

Best Regards,

Garry
near Syracuse, NY


New file uploaded to ultralightdx

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Uploaded by : paulloganradio <paulloganradio@yahoo.ie>
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300 in 30 UL challenge

Paul Logan
 

Hi all,

my thirty days are up and what fun it has been - thanks to Rob Ross for the inspiration.

Not only have new stations been logged but my interest in MW has been totally reinvigorated.

After 300 I got lazy and didnt put in as much time as I might have liked -  I was also messing around with loops.

The final tally was 316 stations logged barefoot from 55 DXCC countries.

Not bad on a radio that cost me approx $14

I am uploading the logged list to the files section for those interested.

73 ( or in our case 72)  and good listening


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

Send instant messages to your online friends http://uk.messenger.yahoo.com


HALF INCH 12.7MM IN DIAMETER FERRITE RODS.

ferriterodman <peter.tankard@...>
 

A VERY BIG HI TO evey one in the ultralight dx group FROM ME Peter
Tankard a new member in sheffield south yorkshire in the uk.Can eny
one please help me I am trying to find some half inch ferrite rods
that are half inch 12.7mm in diameter and are six inches long or more
with very hI Q for the MW LW band I did have some back in the 198s
but I cannot find eny at all now.I will pay very good money for some
half inch ferrite rods that have got a very HI Q for the MW LW BAND
I am a keen dexer on the MW LW BAND and I have head meny local radio
stations from the US at night in sheffield very strong from the east
cost from st jons new fandland and new york and boltamore ON the AM
Band.I did triy amedon some time ago I sent them a sampull of the
half inch ferrite rod that I wanted but thay sent it back to me
saying that thay did not have that materall eny more.The half inch
rods that I had back in the 198s worked in eny transister radio I put
them in using the radios oun mw cail I did have to file the end of
the rod so the cail would slide on in some of the radios. I put the
half inch rod into the Q was so HI it overloded the frunt end of the
radio on strong local stations that are in sheffield and it made very
fint stations from over 280 mills away from sheffield come in very
strong as if thay were in sheffield and this was in the medal of the
day in summer.I would be very gratfull to eny one how can help me. I
cannot find eny half inch rod at all now in the UK I have been puting
ads in the radio magazeens for half inch ferrite rods in the UK for
years now.And somtimes I get a half inch rod sent to me but when I
try it it allwas seems to be the rong permability for the MW LW
band.I have head of an old sony radio that has Very HI Q rods in it
that was only sold in japan if eny one nows the modal nomber and the
years in witch it was made I would be very gratfull or how I could
get a hold of one.all the very best to all the Ultralight dx members
from peter tankard in the UK ps I hope you can all reed my email as I
am Dislexic. Please email me at peter.tankard@bigfoot.com if you can
help me.


Re: Saturday night / Sunday morning Ultralight logs

MarkWA1ION
 

Barefoot. Aligned by our esteemed Ultralight guru Gary DeBock.

Mark Connelly, WA1ION

--- In ultralightdx@yahoogroups.com, "Dennis Gibson" <wb6tnb@...>
wrote:

Barefoot? Radio aligned or stock?

73

--- In ultralightdx@yahoogroups.com, "MarkWA1ION" <MarkWA1ION@>
wrote:

Noted around local midnight (EDT) / 0400 UTC on SRF-39FP:

1359 Spain - fairly loud, about equal to 1360 WDRC/WNJC.

1584 Ceuta - audio popping up once in a while if I nulled 1580
CKDO.


Re: HALF INCH 12.7MM IN DIAMETER FERRITE RODS.

Gary DeBock
 

Hello Peter,
 
     This is Gary DeBock, ferrite rod transplant enthusiast on the west coast of the USA.  Welcome to the group site, and to the worldwide Ultralight DX Team.
 
     As you may have suspected, half-inch diameter ferrite rods are no longer in production, and the only way to obtain them is to purchase old vintage portable radios from eBay or other sources, and remove the rods for your projects.  This is not an ideal situation, but currently it is the only possible supply source.
 
     If you need a high-quality half-inch diameter ferrite rod that is a full 7.25 inch length, may I suggest the Heathkit GR-17 and GR-24 portables, which occasionally show up on eBay, going for around $25 US.  Old Heathkit AM-FM stereo tuners from the 60's (AJ-33, etc.) also have half inch diameter rods, with lengths around 6.25".
 
     The procurement of 3/8 inch rods is much easier, and an experimenter in the USA can usually track down all he needs in short order.  Sony vintage radios (6R-33, TR-6400, ICF-S5W, etc.) all have a 3/8" by 6.25" rod of high quality, and other vintage radios by Panasonic and Sanyo also have similar rods.  These radios (with the exception of the ICF-S5W) are extremely cheap on eBay, and go for around $10-20 on average. Most of them are inoperable, which makes the tinkerer feel a little better when he takes out the ferrite rod  :>)
 
     There will shortly be an article written concerning my 7", 14" and 20" ferrite-bar transplant experiments in the Sony SRF-39FP ultralight radio, which have resulted in ultra-sensitive DX machines.  I hope this detailed article will help those who have interest in this fascinating experimentation.
 
                                                                                 73,  Gary
 
 




Planning your summer road trip? Check out AOL Travel Guides.


Re: a P.S. on my previous post and a reply to Kevin

Peter Tankard <peter.tankard@...>
 

AVERY big hi from peter tankard in sheffield south yorkshire in the UK. I have just jound the Ultralight dx gruop.I find MW LW dexing very xsiting I have head meny local radio stations on mw am from the US on my 1970 grundig yacht boy model 210 and I have been a mw lw dexer sins 1976.I am at the momont trying to find some half inch ferrite rods that are half inch 12.7mm in diameter and or six inches long or more with hi Q for the mw lw band I have got meny ads in the radio magaseens in the uk for the half inch ferrite rods but I do not seem to have eny look in finding eny at all and when I do get some thay are awase the rong permability for the mw lw band back in the 198s I had some half inch ferrite that had very hi Q on the mw lw band I put two six inch long half inch ferrite rods toghter and made one 12 inch long rod and it was as good as using a mw fram aril But the shop were I bout the half inch rods from is no more The rod that I had worked in eny mw lw radio with the radios oun mw lw cails I did not have to change the mw lw cails at all in eny of the radios that I put it in. in some radios that I put the half inch rod in the Q was so HI the it overloded the frunt end of the radio on strong local stations and made very week distant stations sound very good and clear.I have tryed amedon in the us I even sent them a sampul of the half inch rod I was looking for but thay said that thay could not help me but thay did send back my sampul of half inch rod to me.I will pay very good money for some half inch ferrite rods that have got a very HI Q for the mw lw band.Very Best regards from peter tankard my user name is (ferriterodman)


Re: Gary's SRF-39 with the big loopstick

John H. Bryant <bjohnorcas@...>
 

Garry,

It would be great (and helpful) to see a picture of your air-core experiments.... including the current one. If you have any problems at all uploading to the Photio files area, let me know and I'll be glad to help out.

John B.






At 08:24 PM 4/4/2008 +0000, you wrote:

Hi Folks;

Very interesting antenna transplant that Gary performed on the SRF-
39. Any special reason that the coils are way out on the ends of the
ferrite bar? I presume the original antenna and the big transplant
needed the coils separated to allow movement for alignment.

The reason I ask is that on the crystal set discussion group that I
participate in, Ben Tongue (of Blonder-Tongue fame) has pointed us to
an article of his where he examines the efficient construction of
ferrite bar inductors. He has concluded that best performance occurs
with the coil centered and occupying no more than about 1/3 of the
bar's length.

I wonder if the total inductance required for an SRF radio could be
brought about with the two coils closer together and more or less
centered? Perhaps a few turns would have to be removed from one or
the other coil in order to counter any possible increase in total
inductance by having them closer together.

I can't see why an air core loop could not be used as a transplant
antenna. Except for the distributed capacity differences (and I'm
not sure how a ferrite inductor vs an air core one varies) I think
that an inductor is an inductor. The one difficulty I can think of
is how to tune the darn thing for alignment purposes. I guess you
could measure signal strength with a meter at the audio output, and
then remove turns as you go through the same alignment procedure as
with a ferrite bar. It would be a slower process and might involve
adding back fractional turns. The meter would enable the alignment
scheme to work in though you have to turn off the radio and remove
turns.

The reason I bring up air core loops is that crystal set
experimenter's have pointed out quite a bit of variability of
performance in ferrite bars. An air core loop would eliminate this
problem as well as finding a suitable bar.

I have copied Gil Stacy's idea of a variable capacitor and an
inductor as a booster antenna on my SRF-49. Except that I used a 4
1/2 inch air core coil of #21 wire basket wound (left over from a
crystal set project!). I gives a very prominent boost in
performance, so I presume one like it or bigger, of suitable
inductance, might work very well.

Comments?

Thank you,

Garry Nichols











Re: Saturday night / Sunday morning Ultralight logs

Dennis Gibson <wb6tnb@...>
 

Barefoot? Radio aligned or stock?

73

--- In ultralightdx@yahoogroups.com, "MarkWA1ION" <MarkWA1ION@...> wrote:

Noted around local midnight (EDT) / 0400 UTC on SRF-39FP:

1359 Spain - fairly loud, about equal to 1360 WDRC/WNJC.

1584 Ceuta - audio popping up once in a while if I nulled 1580 CKDO.