Date   

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: 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


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: 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)
«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»¥«¤»§«¤»¥«


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: 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.


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 




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


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)


Question on UL external antenna mods.

sloshatron <wa1gwh@...>
 

Hey, John! Nice article on the UL external antenna mods -- thank you.

Have you checked to see whether the turns wrapped around the ferrite
bar for the jack effects the alignment tuning of the bar? I am
particularly interested in the SRF UL, since I have a '49. (Does that
make me a "49er"?)

Seems like it would be best checked with the external antenna connected.

If this effects only the overall sensitivity it may be a moot point
with "big sigs" coming into the set from outdoor antennas.

What do you think?

TNX,

Garry
near Syracuse, NY


3 new TA's for me

Paul Logan
 

Hi all,

three new UL TA catches for me last night including my best yet.


930 CFBC St. John NB, 04:30 "Oldies 93 CFBC" No sign of CJYQ.
650 CKGA Gander, NL, 03:55 "VOCM 590"

and this beauty : )

1110 WBT Charlotte, NC, 06:25, sounded like C2C show. 3664 miles / 5896 km

all barefoot on my new Sony SRF 39FP, kindly supplied by Gary De Bock.

Im absolutely in love with this little marvel, it looks cool, sounds great and seems to just edge out the SRF59 in the selectivity stakes.

IF only I could turn all the Euro stations off -  I hear so many hets on Freqs that I just cant get at.

Oh well such is a dxer's lot.

regards



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


Re: Adding an Antenna Port to an Ultralight

John H. Bryant <bjohnorcas@...>
 

Thanks, Gary....  I do look forward to a DXpedition together, for sure. I'm going to have a difficult time sorting between wanting to use my big gear to chace unQSLed stations and wanting to pile up loggings (hopefully) with a couple of ultralights. I really don't know what I'm going to do!

When you get that transplant article ready, do let me do the fine tuning of the photos.  I can likely turn it around in 24 hours or less, since we are talking about 15 minutes of work, or less.

Now to get at answering that excellent e-mail on the Awards Program.

John B.






At 03:17 PM 4/11/2008 -0400, you wrote:

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
 
 







E100 Hotrodding Assistance Needed!

John H. Bryant <bjohnorcas@...>
 

Help! Help! 

After my success at adding the antenna input port to the Sangean DT-200VX, I started into the E100 last night with the same mod in mind. The back cover came off fine (getting it back on is a bit of a challenge until you learn the trick.)  The receiver is a stack of two or three boards that I now know are connected to a black plastic frame/skeleton that is, itself,  largely hidden by the large upper-most board.  I took the two visible screws outta the board and attempted to remove it from the stack, but it just didn't want to come loose. I lost my nerve at that point and tip-toed my way back outta the radio, got it back together and it made it back to factory condition (whew!) 

This morning I did find some interior photos of the E100 from HongKongRadioer and I discovered that the tuning knob pulls off. More importantly, I sort of infer that you take off the front cover of the receiver, too, and then dismember the stack of boards and sub-assemblies from the FRONT side. DOES ANYONE KNOW IF THAT IS CORRECT???

My first exploration indicated that there is little room for even the 2.5mm audio jack near the ferrite bar on the E100.  I'm thinking that I'll mount one of those audio jacks that fit on circuit boards on the top edge exterior of the radio case (right above the ferrite bar) and run the solder prongs thru the case to a pick-up coil on the ferrite bar. I hate to do this to such a beautiful and useful portable, but I sure do want to be able to hook this puppy to an external antenna.

Finally, as I was making the dial of my table model National SRF-39, I used an analog signal generator and the E100 as a frequency meter. As I was sweeping the generator to establish center points, etc., I got the distinct impression that the stock E100 had sharper IF filters than the much celebrated SRF-39FP. Has anyone compared them side by side for selectivity.

If anyone has been inside  an E100, please speak up........

Thanks,

John B.
















Ultralight First and Records List UPDATED

John H. Bryant <bjohnorcas@...>
 

I've just posted the latest update of the Ultralight Firsts and Records list to the Ultralight Files area of dxer.ca

http://www.dxer.ca/component/option,com_docman/task,cat_view/gid,87/Itemid,77/

Allen Willie of St. Johns, Newfoundland has added two more first country catches (Romania and Denmark) and Paul Logan of Northern Ireland has finally broken the TA barrier from East to West. Following that first TA reception, Paul continued to reach Across the Pond and OBLITERATE most of the World-wide Distance Records for various transmitter powers. His latest catch didn't even make the list yet.... a new record at 1000 watts:

1700 KVNS Brownsville TX, 4-9-08, Sony SRF59 Unlimited (with 2 foot loop)

4794 miles / 7715 km

That is stunning for a cheap little ANALOG pocket radio, even with the assistance of a two foot loop antenna!  The Northwest crew are going to have to struggle to surpass that record this season (or the next, for that matter!)



 

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: E100 Hotrodding Assistance Needed!

dhsatyadhana <satya@...>
 

Hi John:

Sorry, no insights on disassembling the e100, but a few weeks ago I
ran the e100 and the SRF units through an exhaustive, musta been 15-
20 minutes long :-), test to see how they allowed reception of
channels up next to strong locals, and the e100 was the clear winner -
easily the most selective stock ULR out there! My guess is that
they designed it to allow shortwave reception with 5 khz separations,
rather than targetting 9 or 10 khz splits, which is an excellent side
benefit for us!

A couple considerations I see with the e100 are:
1. 910 khz images can be prominent in a strong RF urban area
2. mine is a different model than yours, with a monolithic coil that
covers the entire ferrtite and cannot be slid/tweaked for lower band
performance. Per Gary, my upper band exceeds even the Sony TJ-615
away in sensitivity, (HLAZ-1566 and VOA-1575 beware!), but alas the
lower part of the band (<1000 khz) gets progressively weaker, and the
SRFs easily out-hear the e100 on 540 khz. I believe yours and Gary's
have a movable coil which allows more balanced results.
3. Circuit noise/background white noise: noticeable at low volumes
4. AGC a bit squawky when tuning to strong locals

All in all, I'd say it's one of the better ULR packages, and the only
decent digital set with 1 khz tuning.

73 - Kevin S
Bainbrdige Island, WA



--- In ultralightdx@yahoogroups.com, "John H. Bryant"
<bjohnorcas@...> wrote:

Help! Help!

After my success at adding the antenna input port to the Sangean
DT-200VX, I started into the E100 last night with the same mod in
mind. The back cover came off fine (getting it back on is a bit of
a
challenge until you learn the trick.) The receiver is a stack of
two
or three boards that I now know are connected to a black plastic
frame/skeleton that is, itself, largely hidden by the large
upper-most board. I took the two visible screws outta the board
and
attempted to remove it from the stack, but it just didn't want to
come loose. I lost my nerve at that point and tip-toed my way back
outta the radio, got it back together and it made it back to
factory
condition (whew!)

This morning I did find some interior photos of the E100 from
HongKongRadioer and I discovered that the tuning knob pulls off.
More
importantly, I sort of infer that you take off the front cover of
the
receiver, too, and then dismember the stack of boards and
sub-assemblies from the FRONT side. DOES ANYONE KNOW IF THAT IS
CORRECT???

My first exploration indicated that there is little room for even
the
2.5mm audio jack near the ferrite bar on the E100. I'm thinking
that
I'll mount one of those audio jacks that fit on circuit boards on
the
top edge exterior of the radio case (right above the ferrite bar)
and
run the solder prongs thru the case to a pick-up coil on the
ferrite
bar. I hate to do this to such a beautiful and useful portable, but
I
sure do want to be able to hook this puppy to an external antenna.

Finally, as I was making the dial of my table model National SRF-
39,
I used an analog signal generator and the E100 as a frequency
meter.
As I was sweeping the generator to establish center points, etc., I
got the distinct impression that the stock E100 had sharper IF
filters than the much celebrated SRF-39FP. Has anyone compared them
side by side for selectivity.

If anyone has been inside an E100, please speak up........

Thanks,

John B.


Re: E100 Hotrodding Assistance Needed!

Guy Atkins
 

These are interesting findings on selectivity of the E100. I wonder if the E10 is similar? I have an E10 I picked up at Fry's Electronics for a measly $29.99, and I've been impressed with its performance and value.
 
The E10 has a unique "image avoider" feature. The narrower of the two I.F. filters is actually two filters-- one at 450 kHz I.F., and the other at 455 khz I.F. Depending on which one you choose, it can shift a signal by 10 khz if it is an image, allowing clear reception of the frequency. If it's not an image but a true signal, it stays put.
 
Guy Atkins
Puyallup, WA USA
 
 

-----Original Message-----
From: ultralightdx@... [mailto:ultralightdx@...] On Behalf Of dhsatyadhana
Sent: Saturday, April 12, 2008 10:29 AM
To: ultralightdx@...
Subject: [ultralightdx] Re: E100 Hotrodding Assistance Needed!

Hi John:

Sorry, no insights on disassembling the e100, but a few weeks ago I
ran the e100 and the SRF units through an exhaustive, musta been 15-
20 minutes long :-), test to see how they allowed reception of
channels up next to strong locals, and the e100 was the clear winner -
easily the most selective stock ULR out there! My guess is that
they designed it to allow shortwave reception with 5 khz separations,
rather than targetting 9 or 10 khz splits, which is an excellent side
benefit for us!

A couple considerations I see with the e100 are:
1. 910 khz images can be prominent in a strong RF urban area
2. mine is a different model than yours, with a monolithic coil that
covers the entire ferrtite and cannot be slid/tweaked for lower band
performance. Per Gary, my upper band exceeds even the Sony TJ-615
away in sensitivity, (HLAZ-1566 and VOA-1575 beware!), but alas the
lower part of the band (<1000 khz) gets progressively weaker, and the
SRFs easily out-hear the e100 on 540 khz. I believe yours and Gary's
have a movable coil which allows more balanced results.
3. Circuit noise/background white noise: noticeable at low volumes
4. AGC a bit squawky when tuning to strong locals

All in all, I'd say it's one of the better ULR packages, and the only
decent digital set with 1 khz tuning.

73 - Kevin S
Bainbrdige Island, WA

.


Re: Further comparison of air core vs ferrite bar booster antennas.

satya@...
 

Hi Garry:

Thanks for the detailed blow-by-blow. I too have found that eventually an
air core loop out-pulls a ferrite. I look forward to your pictures!

Quick question: when you say 1.2 inches long on the basket coil, is that
the difference between the inner and outer diameter of the basket? I
assume the "4.1" D" is the outside diameter?

Thanks - Kevin S
Bainbridge Island, WA

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


Air core coil info for Kevin and all.

sloshatron <wa1gwh@...>
 

Hi Folks;

To clarify my coil, the 1.2" is the axial length of the coil. It is
quite short in length and quite wide in diameter (4.1"). It looks a
bit like a loop antenna. I'm not sure if it is "within spec" on the
L/D ratio to be a true loop. I forget that criteria. The longer a
coil gets in relation to its width, the less signal pickup or
radiation it will have.

It is not a typical basket wound coil. One of the Xtal Set Society
guys developed this method of winding where a length of thin wall PVC
has deep slots cut into it lengthwise on one end so that it resembles
the top of a castle peice in chess. The coils created with this form
ended up with the name "rook" coil. I decided to call mine a
basketweave to avoid confusion, but have not succeeded! So now you
know the whole story (apologies to Paul Harvey)!

The 4.1" dimension is the width of the coil measured across it from a
point half way between the inner and outer layers of wire. This
layer distance is only about .2".

Unlike some true basket coils, the turns do not come way in toward
the axis before bending back out. They are quite shallow between
layers. Mine is wound one under, one over -- nothing fancy.

After winding, hot glue is applied across the wire cross-over points
and the form slipped off.

Hope this makes things more clear.

Garry
near Syracuse, NY


New file uploaded to ultralightdx

ultralightdx@...
 

Hello,

This email message is a notification to let you know that
a file has been uploaded to the Files area of the ultralightdx
group.

File : /Sangean DT-210L AM Filter Mod.doc
Uploaded by : knallebo <knallebo@yahoo.co.uk>
Description : AM filter upgrade: Sangean DT-210 series (Roberts R9988) receiver

You can access this file at the URL:
http://groups.yahoo.com/group/ultralightdx/files/Sangean%20DT-210L%20AM%20Filter%20Mod.doc

To learn more about file sharing for your group, please visit:
http://help.yahoo.com/l/us/yahoo/groups/original/members/web/index.htmlfiles

Regards,

knallebo <knallebo@yahoo.co.uk>


Pictures of ferrite bar and air core coils used for booster antenna tests

sloshatron <wa1gwh@...>
 

I uploaded pictures of my test coils. They were each used with the
same variable cap for comparison as booster antennas with my SRF-49.
My previous post describes the test and procedure.

I was planning to show them in position with my SRF-49, but I've taken
the radio off the pine board and disassembled it to study the wiring of
the stock rod.

I'm not very Yahoo literate. Some time ago I set up a Yahoo ID and
being disgruntled once again at yet another ID and password to keep
track of I just typed in my favorite word for our noisy dishwasher.
Hence, I am now "sloshatron", much to my current embarassment because
it is coming up everywhere in this discussion group! (Inspired by The
Jetsons, TV show.)

Garry


IF Filters for the Sangean DT-210

John H. Bryant <bjohnorcas@...>
 

In case you missed it, Michael Slattery, G8PNX, of Sheffield just uploaded a very nice article on putting a much better IF filter in the DT-210. http://groups.yahoo.com/group/ultralightdx/files/ Darn creative solution to fitting in a lager component in an already crowded case. Thanks very much, Michael... Excellent work!


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)

101 - 120 of 31891