Got The AM DX Bug

[flintstone mop]

Hello
I am looking for some ideas for an antenna to grab some DX AM in the MW band. The connection would be to my TS850. I would like to have the antenna outside away from indoor noise and possibly not have to keep re-tuning to maximize a certain part of that band. The interest is in a 1KW daytime on 810 about 60 mi from me.
I have seen the 'miracle' antennas that are coils of wire and when the signal is coupled into a handheld radio that stations come in like a local.
Thanks for any ideas

[KC2TAU]

I've really been digging on this design. I've had great success with TransAtlantic MW and LW DX with it. It does need to be located away from noise sources, though.

http://dl1dbc.net/SAQ/Mwhip/Article_pa0rdt-Mini-Whip_English.pdf

[RolandSWL]

I like simple. When doing MW DX long ago, I had the best results with the lowly loop antenna, a bunch of wire wrapped around a big wooden X. Also, a ferrite bar antenna works well.

RSWL....

[WA2SQQ]

Up until I got my Flex 6500, the best receiver I've used for AM BCB DX'ing was my Kenwood TS-930. For past 20 years I've used a Kiwa Loop - not inexpensive but I've snagged some great DX with it. All the IBOC activity has really decreased the amount of DX we can hear easily.

Now, my 6500 is incredible for this type of activity, especially below the BCB band. Not a stitch of any intermod and I live 3 miles from a 50KW AM power house on 770 khz.

[flintstone mop]

I want to thank you for the replies.
Looks like an antenna with some tuning will help focus on a certain frequency. A large barn door type antenna could be the cause for intermod. I have two Kenwood TS 850's. The first one with a slightly older serial number does fine on my untuned 160M antenna. The second younger version, 4 years newer, likes my dipole for AM stations BUT intermod like crazy. Intermod all the way to 3.6 mhz. The two local stations are 5KW about 3 miles from me. I put the tuner back inline and tuned for 1880, there is no problem with intermod with the "newer" Kenwood on AM. The AM stations are down in signal, which is expected.
The TS850 has quite a following and there are some known shortcomings. Some people snip the built-in attenuator that reduces 500-1500 by 20dB. The attenuators are in-place on both radios. Both radios have identical sensitivity throughout the Ham bands.
NOTHING will beat an R390A for battle conditions and pulling stations out of the noise. But my 390A was sold to buy some other toys.

[W3GMS]

Hi Fred,

I would think your active RX loop would do a great job on the BC band.  Do you still have it? 

73,
Joe-GMS

[W8EJO]

All of the.MW dxers seem to like the ferrite sleeve loop.

http://www.am-dx.com/antennas/FSL%20Antenna%20Design%20Optimization.htm

https://m.youtube.com/watch?v=iqYZcRXCGxM

http://www.dxer.ca/index.php/our-stuff/92-gary-debock

[flintstone mop]

Hi Fred,

I would think your active RX loop would do a great job on the BC band.  Do you still have it? 

73,
Joe-GMS

Hello Joe
No I sold it. It was amplified, as you noted. Without that capability to tune the loop; it becomes that barn door approach and a lot of RF at the radio input. The drawback with many of these digital radios is their inability to handle large RF input. That was always a rare moment with the R390A. Can't beat tubes. You have to pin that carrier level meter HARD to the right to overload an R390A. It is not an elegant radio for surfing the MW/SW bands.
A thought came to me from another website to make a HB loop for AM B'cast and have it remotely tuned using a VARACTOR. An adjustable DC voltage, from the shack!!
There must have been a reason Kenwood uses the attenuator for the AM band in the USA and not for the European market.
So, I'm gonna take a shot at the CC Crane active antenna for the AM band. This unit has a tuning cap as part of the antenna and should avoid the RF overload.

http://www.ccrane.com/Antennas/AM-Antennas/Twin-Coil-Ferrite-AM-Antenna-Signal-Booster

It looks like there is tuning and adjustment for gain. And direct input to a receiver. I'm sure many have seen how the AM antennas, such as the Kaito, magically couple the signal to a simple pocket transistor radio and bring stations out of the mud with little background noise. Kinda like "As Seen On TV" stuff.
I'll take a crap shoot at the Crane unit and give any report later.

I'm not in a building and experimenting mode right now. I am having some medical problems and the energy levels are OK for simple everyday stuff. I'm trying to get my appetite back right now without all of the drama of cramps and indigestion. Some new road to travel on, for now.

I'll check the links out anyway. I'll always enjoy reading and working the grey matter.

[flintstone mop]

All of the.MW dxers seem to like the ferrite sleeve loop.

http://www.am-dx.com/antennas/FSL%20Antenna%20Design%20Optimization.htm

https://m.youtube.com/watch?v=iqYZcRXCGxM

http://www.dxer.ca/index.php/our-stuff/92-gary-debock

Thanks
These devices go on that coupling scheme. And they are amazing. The youtube guy should demonstrate the tuning of the FSL unit. I bet 1070khz station would have popped in there with perfect quieting!!
Anyway, I'm focusing on a direct connection to my transceiver.

[Steve - K4HX]

Don't you have a K9AY?

[flintstone mop]

Don't you have a K9AY?

No Steve that went by the wayside too. That could have been a solution as, that was directional and had a pre-amp. The trees that were supporting the K9AY were cut down for construction for some rental units next door.

[KB2WIG]

F.

Beverage.

B.O.G.

You want one, I know you do. Give in, give in to the temptation. You will feel better soon.


klc

[W3GMS]

Hi Fred,

Within the RX loop family of antenna's, I have always favored the non-tuned amplified ones.  Its really nice not have to mess with tuning them.  Maybe I am lucky, but I have not had any IMD or any other sort of overload issues when using the Wellbrook active loop.  I also hear good things about Pixel.   

A friend of mine locally just built some active receiving loops and now he can hear signals that were not able to be heard on his TX antenna.  Being in a Condo type of living enviroment his noise was extensive.  With a decent null he can frequently get the noise floor down to an S-1 or so while still hearing weak signals.  Its also important to realize that we these loops as you go higher in frequency they are not optimized.  His first 1 meter in diameter active loop with a HB pre-amp worked great on VLF through 40 meters but was not the great on 20 and above.  So he build another version that was half the size (.5M) and it made a large improvement on 20-15-10.

Maybe you should consider this kind of loop again and maybe with an an RF pre-amp where you can adjust the gain. 

Another choice may be something like what Palamor Engineers use to make, but it to had an active preamp in it.

Gl OM

73,
Joe-GMS             

[Steve - K4HX]

I've used those Palomar loopsticks. I was not impressed. Maybe if they were larger and remoted outside, they would produce better results.

[W3GMS]

I've used those Palomar loopsticks. I was not impressed. Maybe if they were larger and remoted outside, they would produce better results.

Never used one Steve.  Years ago I remember people talking about them and I guess it was based on what their expectations were.  If I remember right, they had different plug in's, maybe loopstick based for various frequency ranges.  Some of the guys used them down on 160 to 190 kHz. 

Joe-GMS

[W3GMS]

I just found this on-line review that was done by Monitoring Times.  Based on this single review, it appears its virtue appear in the VLF spectrum and by the time you get to the BC band its performance already falls off. 

http://www.monitoringtimes.com/html/mt1998reviews.html

Joe-GMS 

[W1AEX]

Fred,

At the link below is the easiest wire loop antenna that I have ever used and it works very well throughout the entire AM BCB right up through 40 meters. It's quiet, cheap, directional on the AM BCB and easy to build. There are a couple of embedded YouTube videos on the page showing it tuning across the AM BCB and also being used on 75m and 40m. It's a poor man's K9AY that is bi-directional although you could orient it to favor any direction and then install a terminating resistor if you like. Instead of using a complicated switching system I simply built two of them and left them unterminated, one for N-S and the other for E-W. I built and installed 24dB preamps at the feedpoint of each loop but have found them unnecessary on the AM BCB and 40 meters. No problem catching ZOOMER radio 740 up in Toronto or WCBS 880 in NYC at +20dB over S-9.

73,

Rob W1AEX

http://www.w1aex.com/loop/loop.html

[flintstone mop]

Thanks Rob, Joe, KLC, Steve
The K9AY adaption looks like something doable. I have room on a remote antenna switch to get that into the remaining good feed line to the shack.
The other coax was shot to death by a lightning strike in June. Partially shorted and very strange looking inside for many many feet. We took a surge in the house that came in on the shield and anything that wasn't grounded to station ground was damaged / destroyed. Arc marks on the rack where all of the coax comes into the station. Radios ok. Computer MOBO blown and an external soundcard used for an SDR. A small MFJ SS 600 W amp had a chip blown that drives the front panel meters. The cheapest fix from MFJ.........$38.00.

Trying to find something to hang them on will be a little challenge right now. I printed the schematic.

[WA2SQQ]

One additional comment. I bought the Pixel loop and its by far one of the best VLF / BCB DX antennas I've ever used. The magnetic loop design really pulls the daytime noise way do. On 160 it was responsible for picking up 7 new countries. My noise level was typically an S7, they heard me, but I was not able to hear them! My local 50KW station (WABC 770 khz) is about 2-3 miles away. The loop allows be to get ~ a 20 db null on the local stuff. That reduction brings the noise floor down about 2 s units and in the evening where sky wave prevails the loops directivity is not nearly as sharp. When used on VLF I'm picking up NDB up in Central Canada and the Caribbean. Neither my slopper or inverted L hear any of these. It's not cheap, but it does work. Their secret is the preamp which seems to be very resistant to intermod. At 2-3 miles away from a 50KW station, I'd say it works!

[Steve - K4HX]

The squashed loops are better than the K9AY for BCB work. These designs place the rearward null at or near zero degrees elevation. The null on the K9AY is in the 20-30 degree range. The low angle null is usually better for taking out co-channel interference on the BCB.

Take a look at the Kaz loop.

[flintstone mop]

Pretty HOT success with BC AM.
I received my CC Crane double loop.

http://www.ccrane.com/AM-Antennas/Twin-Coil-Ferrite-AM-Antenna-Signal-Booster

Ya $99.00
OK
The remoted controller is pretty slick. I have it on a 30 foot extension cable Crane calls a PS/2.
I tried many positions of the pick up coil and wasn't getting anywhere. The 240 foot dipole feeding a balun connected to the radio was hearing the stations; and they sounded weak and staticky, except the two locals and a 50kw on 570khz and, of course 50kw 1020. in Pittsburgh Pa.

I switched my K1JJ tuner to the 240 foot dipole. The tuner was tapped for 1.880...The taps make a difference but left them set for 1880.
I laid the CC Crane main pickup coil centered on the K1JJ coil and WOW!!!

Receiving the intended 1KW station on 810khz, 70 miles away, like they are in town!! WEDO...they play oldies between 9am & 3pm. Station is in McKeesport Pa....I'm in New Castle Pa.
I tune up and down the BC band and hear a lot of stations...I have to always re-tune the CC Crane controller to peak up the signal.
The TS 850 has modified audio and it hears 30hz-10khz audio...Smoooth audio
This is daytime reception.

[WA2SQQ]

Whats' the info on the K1JJ tuner?

[KB2WIG]

 

Whats' the info on the K1JJ tuner?

http://amfone.net/ECSound/

There are many flavors.

http://amfone.net/Amforum/index.php?topic=10989.0


http://amfone.net/Amforum/index.php?topic=30759.0


KLC

[flintstone mop]

Whats' the info on the K1JJ tuner?

http://amfone.net/ECSound/

There are many flavors.

http://amfone.net/Amforum/index.php?topic=10989.0


http://amfone.net/Amforum/index.php?topic=30759.0


KLC

Thanks KLC
I do not see anything about the tuner in the first link connecting to tom, K1JJ....maybe I'm scanning too fast.

The last two links definitely have some good pictures and info on that tuner.
If you do a lot of QSYing you will eventually get pretty good at selecting the taps and ballparking the vacuum cap.

[KB2WIG]

F,

I shudda used this link,

http://amfone.net/ECSound/K1JJ13.htm

The First link I gave has the Tuna listed as  ***** A Simple and Effective High Power Antenna Tuner *****