zl2taw
Member
Yeah even with the loop I have the same issues here with the 6-7mHz range
I just cant seem to isolate where the RFI is coming from
Wellbrook ALA1530 vs PAR EF-SWL. Who'll win?
- Thread starter TassieJay
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Yeah even with the loop I have the same issues here with the 6-7mHz range
I just cant seem to isolate where the RFI is coming from
Occasionally I have that problem too, and can't be nulled out. That says to me the noise is mains-borne and travelling down power lines for some distance. That, or multiple neighbours in the vicinity have purchased the same cheapie special plasma TV.
Hertzian has a great point: floating your setup. When the local noise has eased somewhat, I can get comparable, and sometimes even slightly better SNR with a battery portable & long wire compared to the 1530. But that's only rare occasions.
Whoa, a 300 Megohm resistor... a piece of perspex perhaps? 5-10 megohm is about as high a resistor as you can get around here - but that'd probably be fine for this application anyway, I'd have thought.
That's the problem with these new, wide-spectrum digital noise sources. They are much hard to track down than simple power line noise. (I'm being sarcastic as PLN can be tricky to isolate too.)
I've tried to hunt down the source of my 6-7Mhz noise and the problem is the 'strongest' signal will change by the time I can get out and start searching.**
I believe it's a combination of old homes (with poor or inadequate grounding), lack of a filtered surge protector(s) on digital devices and poor power line maintenance by utility companies. (I don't think it's just power utilities though.)
They simply just don't care about a little HF leakage here or there. These companies are trying to save costs any way possible so they're not about to send out crews to check out some minor complaint from a radio geek.
**I finally got a much needed DC-DC converter for my Perseus. I plan on driving around with my Perseus active while in the SUV. I have just a simple hamstick whip antenna but it should make for some interesting RFI discoveries.
I've tried to hunt down the source of my 6-7Mhz noise and the problem is the 'strongest' signal will change by the time I can get out and start searching.**
I believe it's a combination of old homes (with poor or inadequate grounding), lack of a filtered surge protector(s) on digital devices and poor power line maintenance by utility companies. (I don't think it's just power utilities though.)
They simply just don't care about a little HF leakage here or there. These companies are trying to save costs any way possible so they're not about to send out crews to check out some minor complaint from a radio geek.
**I finally got a much needed DC-DC converter for my Perseus. I plan on driving around with my Perseus active while in the SUV. I have just a simple hamstick whip antenna but it should make for some interesting RFI discoveries.
Oops - I meant 3 megohm. Actually just 1 megohm in series, but anywhere from 1 to 3 seems to be fine.
Part of my floating setup is not only due to a noisy ac line where the gear is located, but also while I have tested for a good AC safety ground, one outlet acts like a long elevated random wire in the walls from an RF standpoint. It took me a long time to figure out why I was getting strange directional results and bizarre analyzer readings since I couldn't establish a good ground indoors. Thus I went isolated, and ran my own radials with much better results and far less sensitivity to the indoor environment - although obviously it still isn't like being outside. Plus I choke almost all antenna feedpoints.
Keep an eye out for new solar installations too - many grid-tie systems use "mppt" charge controllers, which are dc switchers and even increasing in popularity for the 12v hobbiest crowd. Some may be clean, but for now I'm only running with the older "pwm" style controller which doesn't use high-frequency dc switching techniques.
benbenrf
Member
Wellbrooke - fantastic loop antenna - throughout the HF spectrum, but especially in the lower bands.
For those who would like to read up on some additional detail take a look at the following online PDF article:
http://www.cliftonlaboratories.com/Documents/Loop vs Loop Final-Final.pdf
Jack Smith designed the pre-amp in Wellbrooke's latest HF loop offering - and a darn nice job he done of it as well.
For those who would like to read up on some additional detail take a look at the following online PDF article:
http://www.cliftonlaboratories.com/Documents/Loop vs Loop Final-Final.pdf
Jack Smith designed the pre-amp in Wellbrooke's latest HF loop offering - and a darn nice job he done of it as well.
GKolo
Member
Who sells this antenna ? I have a Kaito 1103 also and would like to try it.
No, he designed the preamp for Pixel Technologies Pro-1B ... not the Wellbrook.
You can buy at the link below but this antenna would *destroy* your Kaito. It's not for use with portable SW radios. You would need a HF receiver at a minimum.
North American Versions
The Wellbrook 1530 works just fine with my Degen DE1103. Admittedly it works that little bit better with the Kenwood TS2000, but $100 vs $2000 radio, you'd want to hope so!
Don't forget that the little high impedance matching circuit is switched out when you plug in an external antenna to the 1103, and if you have any problems, a real RF attenuator operating at the front end, not the IF stage, is available to assist.
Don't forget that the little high impedance matching circuit is switched out when you plug in an external antenna to the 1103, and if you have any problems, a real RF attenuator operating at the front end, not the IF stage, is available to assist.
mondomusique
Member
Hehe, no I don't think the Wellbrook would destroy a portable, especially in North America (no flamethrowers other than maybe WWCR). The general quality of the Wellbrook antenna is a lower noise floor not higher gain. I used a Wellbrook ALA-100M for a time with a Sony SW55 portable with the only problem being connecting the antenna's PL259 connector to the portable's 1/8 inch antenna jack (my solution involved adapters and rubber bands to prevent strain on the portable's antenna jack -- not ideal).
I would like to see some signal gain charts for the various Wellbrook antennas, though.
Perhaps not signal gain, but something similar: a gain correction factor chart calibrating V/M field strength to uV output for the ALA1530 can be found here:
http://www.wellbrook.uk.com/images/ALA1530cal.pdf
mondomusique
Member
Hey TassieJay:
It took me awhile, but that is the kind of chart I'm talking about. It would be good to see all the Wellbrook antennas on the same chart to see how the different model compare over 0-30 MHz.
Did Jack Smith do a 0-30 MHz chart comparing the gain of the Pixel Pro 1B against the Wellbrook ALA-1530?
karldotcom
Member
How about something this big?
TONYNYPD
Member
Hey Folks:
Just wanted to share my experince in as well.
Been running a Par for about 2 years. Kinda the same way Ridgescan had his setup. I added about 106 feet of wire off the second lug and ran it in a vee. The longer wire out into a tree about 15 feet off the ground maxed out to about 18 feet at the tree. Grounded at both ends.
Worked great for me. Tons of contacts and I've been making some nice vids on my youtube page.
Not really usable during the day with the noise, but i was happy.
Was eyeing a loop for a few years, heard so much about them, some of you guys posted some great vids and i finally made the plunge.
Honestly i expected maybe a 20% increase in signal strength and maybe the same in lower noise.
Mounted mine about 70 feet from my house, ran it with LMR-240 up on a rotor. Loop is about 15 feet off the ground.
Holy Hannah was I surprised. This thing kills on every part of the band. Never had to use attenuation much on my Excalibur Pro, but i use it now all the time. I've tested it head to head with the old setup. No switches, just hot swapping the coax.
Take a look
Welbrook 1530+ Imperiuim vs Par SWL long wire - YouTube
Wellbrook Loop 1530S+ Imperium Vs Par-SWL LF Beacons - YouTube
Wellbrook loop 1530+ Imperium Vs Par-SWL with added wire - YouTube
Wellbrook Loop Vs Par-SWL - YouTube
Wellbrook loop vs Par-SWL longwire antenna on 15 meters - YouTube
Just wanted to share my experince in as well.
Been running a Par for about 2 years. Kinda the same way Ridgescan had his setup. I added about 106 feet of wire off the second lug and ran it in a vee. The longer wire out into a tree about 15 feet off the ground maxed out to about 18 feet at the tree. Grounded at both ends.
Worked great for me. Tons of contacts and I've been making some nice vids on my youtube page.
Not really usable during the day with the noise, but i was happy.
Was eyeing a loop for a few years, heard so much about them, some of you guys posted some great vids and i finally made the plunge.
Honestly i expected maybe a 20% increase in signal strength and maybe the same in lower noise.
Mounted mine about 70 feet from my house, ran it with LMR-240 up on a rotor. Loop is about 15 feet off the ground.
Holy Hannah was I surprised. This thing kills on every part of the band. Never had to use attenuation much on my Excalibur Pro, but i use it now all the time. I've tested it head to head with the old setup. No switches, just hot swapping the coax.
Take a look
Welbrook 1530+ Imperiuim vs Par SWL long wire - YouTube
Wellbrook Loop 1530S+ Imperium Vs Par-SWL LF Beacons - YouTube
Wellbrook loop 1530+ Imperium Vs Par-SWL with added wire - YouTube
Wellbrook Loop Vs Par-SWL - YouTube
Wellbrook loop vs Par-SWL longwire antenna on 15 meters - YouTube
Well, for LF frequencies in particular, there is no comparison due to the limited length of the PAR antenna lead. For typical HF frequencies (2-30Mhz) you're going to see much better noise suppression thanks to the nature of the loop antenna. The active amplifier helps too. Pull the power plug from the box and you'll see how much your USB signals will drop out.
On your PAR antenna, did you say that you grounded both sides? Both sides of what? Did you ground the primary antenna wire and the balun? If so, that turns it into a short beverage antenna which makes it directional. So it'll pick up frequencies along the direction of the wire instead of the typical broadside lobes of the wire.
BTW, the Imperium model has newer electronics than older Wellbrook models so it should be even better. I happen to get the newer one under warranty and it works OK for me.
If you have the space for a large wire loop (and low noise floor), then I would recommend the ALA100LN versus the 1m loop.
If you think the gain of the 1m loop is impressive you should try the ALA100LN with a 150ft wire loop.
IMHO, it has even lower noise than the 1m loop models. The only caveat is that the wire loop needs more space -- and height really makes a difference.
Thats ok guys. I liked my PAR SWL but I like my Pixel loop better. Had the lousey loop from across the pond and it was caca del toro. Mine has been up over 2 years and hasnt lost a signal
TONYNYPD
Member
Yep Nick
It is setup as a mini Beverage. Grounded at the balun and the far end of the antenna. I tried it with just the ground at one end and it was much quieter with both running. Love the Par, served me well. but the 1530+ is just a far superior Antenna.
I read your post and watched all the vids, some friends told me about their experience, but until you experience it yourself it's hard to explain.
I don't have a ton of trouble with noise so I don't know how much the rotor will do. Some have said the Loop is more directional than most think. I have to play with it to see. To me so far i have equally strong sigs from all directions on skywave.
I have tons of room, So I'll investigate the ALA100LN
Thanks
T
It is setup as a mini Beverage. Grounded at the balun and the far end of the antenna. I tried it with just the ground at one end and it was much quieter with both running. Love the Par, served me well. but the 1530+ is just a far superior Antenna.
I read your post and watched all the vids, some friends told me about their experience, but until you experience it yourself it's hard to explain.
I don't have a ton of trouble with noise so I don't know how much the rotor will do. Some have said the Loop is more directional than most think. I have to play with it to see. To me so far i have equally strong sigs from all directions on skywave.
I have tons of room, So I'll investigate the ALA100LN
Thanks
T
ka3jjz
Wiki Admin Emeritus
From a purely propagation standpoint, loops and end fed wires respond totally differently. You would do well to keep both, and use a switching arrangement to go between the two. If a signal is not coming in well on the loop, switch to the wire, and vice versa.
Many of the more serious DXers (that have the space to do this) keep a couple of different antennas handy for just this reason. It's very difficult to accurately model how a signal is going to arrive at your location. In this case the old YMMV really does apply, particularly with HF sigs...Mike
Many of the more serious DXers (that have the space to do this) keep a couple of different antennas handy for just this reason. It's very difficult to accurately model how a signal is going to arrive at your location. In this case the old YMMV really does apply, particularly with HF sigs...Mike
For me personally I gave up on wires. During daytime escapades I find too much QRM/QRN on the high bands. I have totally relied on my Pixel loop to enjoy my listening...be it CW or otherwise. When I had the Wellbrook I got rather frustrated with more static than I thought. Obviously it wasn't my location since the Pixel doesn't show the same behavior. I am VERY happy with my investment.
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