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Receive Antennas (below 30MHz) - For all topics related to receive antennas used on HF, MW, LW, etc. For transmit antennas use the Amateur Radio Antennas forum.

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Old 01-20-2018, 2:07 PM
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Default antenna extension experiment

In another recent thread on this forum, ridgescan had mentioned that he lengthened his PAR EF-SWL to about 100' and laid it out in a "L" configuration.

We had a bit of a thaw in the ice cold WX here yesterday so took the opportunity to try a similar thing with my PAR. The antenna has been in use at my QTH for the past couple years or so and has provided good results on LW, AM, and HF, however, always experimenting with antennas here so gave it a go.

The original antenna is about 45' long and runs NE-SW. Added 10' to this and then made an approx. 90 degree turn and ran an additional 45' SE-NW to a tree. Overall length is about 100'... no scientific reason, just happened to be where a convenient tree is located. Used #18 Polystealth which is what was used on the stock antenna. Nice stuff to work with, very strong and stealthy.

Tried out the new antenna early this morning on LW. Logged 134 NDBs in a two hour period beginning at 1000Z. Can't recall ever logging so many beacons in a couple of hours. The action seemed to come from all points of the compass. From my Michigan QTH heard the following DX:

East, 350 DF Deer Lake, 356 AY St. Anthony, and 390 Stephenville all in NL.

North, 208 YSK Sanikiluaq NU.

West, 212 YGX Gillam, 244 TH Thompson, 250 Flin Flon, 305 YQ Churchill, and 370 YBV Berens River all in MB; 317 VC LaRonge SK; and 344 BKU Baker MT
.
South, 248 PQF Mesquite TX (an ATNO for me), 257 SQT Melbourne, 326 PKZ Pensacola, 332 FIS Key West, and 344 JA Jacksonville all in FL; and 415 CBC Cayman Brac, Cayman Is. CYM.

My first impression with this new antenna configuration is favorable. Hey, maybe it was just some exceptionally good propagation Time will tell. Also need time to check it out on the AM BCB and HF.
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Old 01-20-2018, 3:43 PM
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Cool! Give it a good run and let us know
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BC785D to Diamond D130J @50'
IcomR71A, RS DX-160 to Wellbrook loop @50'
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Old 01-21-2018, 1:16 AM
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You do realize that you're monitoring a VERY low portion of the HF spectrum? Thus the 45ft primary element isn't really efficient for your type of monitoring. The longer wire is just bringing your antenna closer to resonance.

Do you have access to that field to the south of your property? A Wellbrook loop would be ideal for hunting NDBs and since it's directional you'll be able spin it around on a rotator. Just get it as far away from the house(s) as possible to avoid RFI. The loops are ideal for LF and MW parts of the spectrum.

The LF specific Wellbrook loop is actually quite affordable:

https://www.loop-antennas.com/wellbr...ican/ALA1530LF
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Old 01-21-2018, 7:54 AM
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Quote:
Originally Posted by devicelab View Post
You do realize that you're monitoring a VERY low portion of the HF spectrum? Thus the 45ft primary element isn't really efficient for your type of monitoring. The longer wire is just bringing your antenna closer to resonance.

Do you have access to that field to the south of your property? A Wellbrook loop would be ideal for hunting NDBs and since it's directional you'll be able spin it around on a rotator. Just get it as far away from the house(s) as possible to avoid RFI. The loops are ideal for LF and MW parts of the spectrum.

The LF specific Wellbrook loop is actually quite affordable:

https://www.loop-antennas.com/wellbr...ican/ALA1530LF
Did you read his logs?
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BC785D to Diamond D130J @50'
IcomR71A, RS DX-160 to Wellbrook loop @50'
IcomR75,
'54 SX-88 #127 to 100' endfed wire/9:1 trans. @40'
RS Pro 2066 in truck to Larsen Tribander
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Old 01-21-2018, 1:14 PM
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Quote:
Originally Posted by devicelab View Post
You do realize that you're monitoring a VERY low portion of the HF spectrum? Thus the 45ft primary element isn't really efficient for your type of monitoring. The longer wire is just bringing your antenna closer to resonance.

Do you have access to that field to the south of your property? A Wellbrook loop would be ideal for hunting NDBs and since it's directional you'll be able spin it around on a rotator. Just get it as far away from the house(s) as possible to avoid RFI. The loops are ideal for LF and MW parts of the spectrum.

The LF specific Wellbrook loop is actually quite affordable:

https://www.loop-antennas.com/wellbr...ican/ALA1530LF
Started with the LW freqs because the beacons are easy to identify and have extensive logbooks here for comparison purposes.. Another LW session this morning, although briefer, snagged 3 ATNOs for me. Not surprisingly, more wire should equal better performance on LW. So my initial impression is the additional length has yielded some improvement on the low end of the spectrum.

Working my way up the spectrum, the AM band will be investigated next. This will be more tedious as the stations are harder to identify. Some stations are real good about identifying but nowadays most seem to ID with some slogan meaningless to anyone other than a local. Even the TOH ID can be ambiguous. Most Canadian stations hardly ever give their callsign. Anyway, there are a number of AM bandscans in my logbooks here for comparison purposes so will be working on that as time permits. If it starts looking like improvement also on AM, the antenna might get extended even further in something like a "Z" pattern.

Regarding the field, my thought there may be a BOG to be deployed at night and reeled in at daybreak. Would like to go out at least 500'.
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Old 01-21-2018, 9:07 PM
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Heard 252 Algeria here earlier this evening strong enough to cover the bad local QRM until it faded out at about 0115Z. First time ever hearing a LWBC station here.
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Old 01-21-2018, 9:19 PM
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Keep us informed of your findings WA8ZTZ!
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Old 01-21-2018, 10:34 PM
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Quote:
Originally Posted by WA8ZTZ View Post
Heard 252 Algeria here earlier this evening strong enough to cover the bad local QRM until it faded out at about 0115Z. First time ever hearing a LWBC station here.
Hell you're already doing better with yours than I ever will!
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BC785D to Diamond D130J @50'
IcomR71A, RS DX-160 to Wellbrook loop @50'
IcomR75,
'54 SX-88 #127 to 100' endfed wire/9:1 trans. @40'
RS Pro 2066 in truck to Larsen Tribander
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Old 01-22-2018, 7:23 AM
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Originally Posted by ridgescan View Post
Hell you're already doing better with yours than I ever will!
If you are referring to the Algerian station, that would be almost impossible on the West Coast. OTOH, you are well positioned for some South Pacific DX which would be impossible here.
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Old 01-22-2018, 9:37 PM
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Quote:
Originally Posted by WA8ZTZ View Post
If you are referring to the Algerian station, that would be almost impossible on the West Coast. OTOH, you are well positioned for some South Pacific DX which would be impossible here.
I'm referring to everything you logged in your thread. I seems that new configuration is working out very well for you. How far up from the ground is it BTW?
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BC785D to Diamond D130J @50'
IcomR71A, RS DX-160 to Wellbrook loop @50'
IcomR75,
'54 SX-88 #127 to 100' endfed wire/9:1 trans. @40'
RS Pro 2066 in truck to Larsen Tribander
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Old 01-22-2018, 11:14 PM
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Its nice the extra length wire is picking up VLF signals better, but I would think a good active vertical whip would do a better job. 100ft of wire maybe 20ft off the ground for VLF is like using a 6ft length of wire horizontal less than a foot off the ground for 80m reception. Its still really inefficient.

There is a group that was trying to do a trans Atlantic contact on VLF and their go to receive antennas seem to be short active whips. If your in an area that is quiet enough to log the stuff your getting, you would probably do very well with a high end active whip.

I have a good active whip and VLF signal levels are a lot higher on it compared to my various horizontal wire antennas, but below the AM BCB my noise level goes through the roof in the big city.

Here is the active whip I built wtih a little history of its inception: http://www.arrl.org/files/file/Techn...df/0109031.pdf
prcguy
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Old 01-23-2018, 7:20 AM
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Quote:
Originally Posted by ridgescan View Post
I'm referring to everything you logged in your thread. I seems that new configuration is working out very well for you. How far up from the ground is it BTW?
Antenna slopes from about 25' down to 8' at the vertex then back up to about 10'. A rather hasty installation in the thaw we got starting last week. Plan on getting it higher when the WX improves.

W1AW copy on 80 and especially on 40 has been poor here lately in the evening but noticed much improved reception last evening with the extended antenna.
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Old 01-23-2018, 7:28 AM
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prc,

Tnx for link to QST article.
Have a MFJ 1020C active antenna here that has given good results on AM BCB.
Yes, noise is an issue... an ongoing battle fighting the QRM.
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Old 01-24-2018, 1:16 PM
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Had an opportunity this morning to try out the extended antenna on the AM band. Did not have enough time to scan the entire band but was able to do a partial bandscan from 530 to 1000. Daytime is a good time for such an experiment due to stable band conditions and no QSB. My logbooks are able to provide comparison to past AM daytime bandscans done with the previous shorter antenna.

In every case there was a definite improvement. The "fringe area" (to borrow a TV term) (out about 60 -100 mi from my SE MI QTH) lower powered stations were all at least several S-units higher. The most noticeable improvement was with higher power stations out 250 - 300 mi which now sounded like locals. These are stations that were readable before but noisy. WSCR 670 "The Score", and WGN 720 in Chicago were S9 and WBBM 780 also in Chicago was S6-7. WLW 700 Cincinnati was S8-9. CFTR 680 and CJBC 860 Toronto were S6-7 and CFZM 740 "Zoomer Radio" Toronto was S9+20.
Several stations were heard on frequencies where nothing had been heard in the past.

Even though the extended antenna provided an overall improvement, there were a number of cases where there was a mix of 2 or 3 stations on the same frequency. For serious AM BCB DXing a loop antenna is really the way to go. This becomes even more evident at night when practically every frequency will have stations that need to be separated.

Last edited by WA8ZTZ; 01-24-2018 at 1:23 PM..
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