HiFERs Sunday & Monday
Posted by John Davis on August 27, 2013 at 18:39:12.
Re: Saturday Afternoon HiFERs (Thursday Update)
August 1: Our forecast is looking stormy again the next couple of days, so I returned to the field about two hours before sunset today, just to be sure of at least one day of monitoring this week. In ascending order, I saw USC, MP, EH, and NC, all taking turns at audibility and dogbones.
No SIWs today, and no EDJ...although I got my hopes up when I saw something fade in around Bob's spot. It wasn't EDJ's FSK, however. It turned out to be a specimen of MLG Code (Multi Level Gibberish), created by mixing in my hard limiter when EH and NC were strong simultaneously.
As strong as the watering hole stations were at various times, I had high hopes for the conventional CW signals, but most were totally inaudible and none of them were truly identifiable. GNK was the best of the bunch, with one character at a time making it through every so often. AJO was lost in multiple weak carriers. Nothing at all from FRC today, which is certainly unusual.
Codar started picking up about 45 minutes before sunset, but that was better than the QRN on 1750 and 2200 meters from the severe storms up in Nebraska.
John
EDJ QRV starting tonight 8/2...
Posted by Bob WA1EDJ on August 02, 2013 at 14:52:36.
EDJ will be QRV ( I think that's the correct Q? ) starting tonight throughout the weekend. Looks like TS's will be south of my QTH for a few days.
Bob EDJ.....
Hifer
Posted by Brian Chapman on August 03, 2013 at 02:52:25.
I've been chasing ndb's for a while now with good success. I've also been hoping to copy a lowfer,medfer or hifer!!! Today was the day !!! I finally caught a hifer FRC about 9am local PDT here in the Elko,NV area. I am interested in putting a hifer on the air. I have a 20m HF stick and a metal sided pole barn style garage. I would be willing to pay for a plug and play unit with the letters BC. I am using Argo to copy ndb's but am still pretty green regarding qrss. At this point I have never yet copied a medfer or lowfer. I will be joining LWCA shortly and hope to become very active and knowledgeable in the group.Eventually I would like to put a lowfer on the air as well.Any help would be appreciated. Brian nb9e
Re: Hifer
Posted by Pat Bunn on August 05, 2013 at 16:49:30.
In reply to Hifer posted by Brian Chapman on August 03, 2013
Email me. I can supply you with a board or a board and parts or the whole thing assembled. Just pay for the parts. LWCA and Hifer !!!
pbunn@patbunn.com
Posted by Brian Chapman nb9e on August 07, 2013 at 01:34:35.
I joined the LWCA today and ordered the Hifer beacon as well. Looking forward to putting BC on the air from DN20fr
Re: LWCA and Hifer !!!
Posted by John Davis on August 07, 2013 at 05:05:45.
In reply to LWCA and Hifer !!! posted by Brian Chapman nb9e on August 07, 2013
Welcome aboard, Brian!
Re: Hifer
Posted by Mark on August 07, 2013 at 09:34:03.
In reply to Hifer posted by Brian Chapman on August 03, 2013
Hi Brian! Speaking of NDB's have you happen to have heard the Reno NDB, NO on 351 recently? The FAA decommssioned it a couple of years ago but it remained on the air. I last logged it in May of this year. There are a couple of us over in on the west slope in Northern UT that look forward to hearing your beacons.
73, Mark Re: Hifer
DN41
Posted by Brian nb9e on August 08, 2013 at 17:27:35.
In reply to Re: Hifer posted by Mark on August 07, 2013
Checked for NO 351 kHz Reno this morning around 3:30 am local without success !!! I did copy NY very strong out of Enderby though. Re: Hifer
Posted by Mark on August 09, 2013 at 13:15:01.
In reply to Re: Hifer posted by Brian nb9e on August 08, 2013
Tnx Brian! That's what I expected! Will have to keep an ear out for it to see if it ever returns. No NDB's in Nevada now! We only have one left here in Utah.
73, Mark, Ku7z North Country Radio
Posted by Brian on August 10, 2013 at 01:05:17.
What is the groups experience with the LF90 and MF90 for Lowfer and Medfer use ? I've been eyeing these for a while !!! I am also very interested in building home brew antennas for these bands .
Re: North Country Radio
Posted by John Davis on August 10, 2013 at 04:08:14.
In reply to North Country Radio posted by Brian on August 10, 2013
I'm not familiar with the MF90, but I do have one of the LF90 units. It seems to be a fairly sound design in general, but it does have a few drawbacks.
For one, it's hard to directly measure DC input power to the final PA transistor, which you need in order to prove compliance with the FCC power limit. You pretty much have to measure the total current to the transmitter under carrier on and off conditions, then subtract to find the difference between them, then multiply that difference by the supply voltage in the carrier-on condition. That's awkward, but it certainly can be done if you dont mind the inconvenience.
The final amplifier is not Class D nor E, and is not even particularly high efficiency for a Class C. Most operators consider getting every last milliwatt of RF out of the legal 1 watt input rather important, considering the losses inherent in most installations.
The crystal timebase to which the PLL is referenced is OK if you're in a temperature controlled environment, but not so great if the unit is outdoors--which is where the transmitter generally must be, to avoid having to shorten your antenna because feedline length between the transmitter and antenna is included in the length limit. It would be advisable to replace the on-board oscillator with a TCXO; or perhaps feed a reference frequency to it from a stable source in the house; or else find a way to temperature-stabilize the crystal in the LF90 itself, such as by attaching a positive temperature coefficient thermistor to it as a heat source. (Alternately, this season I'm considering using the LF90 indoors merely as an exciter to drive a better final amplifier located at the base of the antenna.)
And finally, although the unit does contain an internal beacon keyer nominally capable of CW or BPSK, no one seems to use the original plain BPSK format any more. It has basically been replaced by WOLF mode, a more modern form of BPSK, which the LF90 doesn't do. The CW mode is adjustable from normal Morse speeds down to very slow QRSS modes, but with one big catch--the speed is set by a potentiometer! Believe me, it's time consuming to get your keying speed right when trying to set up for QRSS60.
(Correct dot length and interelement spacing are both vital if you want the Argo program's matched filtering to distinguish them properly at the receive end. If your element length is a bit too short, the receiving operator will have to set Argo for a faster mode than you are trying to send. Let's say you're trying for 60 second dots, but are actually sending 45 or 50 second dots. There is no setting in Argo for these, so the other guy will have to set Argo for 30 second dot length instead of 60 in order to keep the trace from being an unreadable blur...but that sacrifices 6 dB of detection capability that the slower speed/longer dot length would give you. Unfortunately, some operators don't understand the matched filter concept and try to use non-standard speeds or shorten the interelement spacings to save transmission time. They might as well just back down to the next faster standard speed, 'cause that's what the guy tuning them in is going to have to do at his end in a true DX situation.)
To summarize, the LF90 is not a bad product. If your primary objective is coverage out to 60-90 miles with conventional CW, or farther on a really quiet winter night, then I expect it's as good as any. But it's not ideal for modern slow modes that need good carrier frequency stability and accurate keyer timing to work well.
John
Re: North Country Radio
Posted by Lee on August 12, 2013 at 03:23:21.
In reply to Re: North Country Radio posted by John Davis on August 10, 2013
Any suggestions on making the final a more efficient [higher output] final. 1 watt into the final is great. 95% of that out is greater. We all love to hack! Re: North Country Radio
Lee
Posted by Lee on August 12, 2013 at 04:44:49.
In reply to Re: North Country Radio posted by John Davis on August 10, 2013
After my 95% remark I thought I should look it up. Been a while since school and theory. Class A 50% max, class AB 60-70%, Class C 78.6% into an inductive load. I'm thinking I should use my AM88 as a driver into the PA of a good CMOS PA. Any LF90 hacks or good CMOS class C PA suggestions. Re: North Country Radio
Lee
Posted by John Davis on August 12, 2013 at 17:46:11.
In reply to Re: North Country Radio posted by Lee on August 12, 2013
Actually, Lee, even those efficiencies for Class A through C are pretty optimistic and only apply under very specific peak operating conditions.
It is possible, though, to do much better than Class C with most of the switching-mode finals used by LowFER operators these days. It is also entirely feasible to use an LF90 or AM88 or other signal source as an exciter with such amps if you provide means in your final to square up the drive signal before applying it to the switching transistors. The co-moderator of this message board has a circuit for this purpose that I like a lot: TAG LF 1W Power Amp.
Note that this circuit was designed for a nominal 10 mW drive, so you may have to pad your driver output quite a bit! It's sort of an all-inclusive design and you might not need all of it in your situation. The 24 volt variable supply and 75 ohm dropping resistor, for instance, are a great way of stabilizing power for tuning fluctuations. But if all you've got available at the site is 12 volts from a battery, you could leave them out for normal operation and simply do the best you can with your output matching circuit and loading coil adjustments. (Or better still, use them for tuneup until you achieve the desired power input simultaneous with 12 volts at the metering point, and then bypass the 75 ohm resistor and go battery-only.)
Because of the switching design, the amp is not suited for transmission modes that require linear amplification, but can handle on-off keying (like CW/QRSS) and FSK just fine.
John
Re: North Country Radio
Posted by Pat Bunn on August 12, 2013 at 17:47:09.
In reply to Re: North Country Radio posted by Lee on August 12, 2013
Class D minimum - Class E even better. Class C is a waste of power - Class A, AB or B is for linear operation and a big waste of power for CW.
Class D is very easy with efficiencies above 90% likely more below 2 MHz.
LF sensitivity of e-probe and loop
Posted by Garry, K3SIW on August 13, 2013 at 00:34:06.
I've submitted 3 posts on recent daytime SNR measurements of NDBs comparing a 5' e-probe with a 10' shielded loop. The posts, an attempt to convey the methodology and results, can be found in the LWCA Forum at http://lwca.org/community/YaBB.pl?num=1376352581. Hardly definitive but hopefully useful.
73, Garry, K3SIW, EN52ta, Elgin, IL
Re: North Country Radio
Posted by Lee on August 13, 2013 at 01:26:13.
In reply to Re: North Country Radio posted by John Davis on August 12, 2013
Thanks. Great info. My project for this coming season mid September is an Ufer ground connection to my patio concrete. I will attempt an external PA for Fall 2014. Plenty of time to build. Re: North Country Radio
Lee
Posted by Lee on August 13, 2013 at 05:58:27.
In reply to Re: North Country Radio posted by John Davis on August 12, 2013
The TAG LF 1W does not note any LP filtering after the PA. I'm thinking that I would need to add that. Re: LF sensitivity of e-probe and loop
Lee
Posted by Lee on August 13, 2013 at 05:59:50.
In reply to LF sensitivity of e-probe and loop posted by Garry, K3SIW on August 13, 2013
Thanks Garry. I am following all of your posts on this subject. Re: North Country Radio
Lee
Posted by John Davis on August 13, 2013 at 16:46:45.
In reply to Re: North Country Radio posted by Lee on August 13, 2013
Yes, that's just the amplifier portion by itself, so you would need to add whatever filtering/matching/loading you prefer. For those interested in the antecedents of the key features of this design, Lyle's original amplifier is included as part of the All-In-One Transmitter article in the LWCA Library, where he includes an harmonic filter in case you don't trust your matching arrangement by itself. You can find the power stabilizer circuit discussed in a related article there.
John Re: North Country Radio
Posted by Lee on August 14, 2013 at 00:37:40.
In reply to Re: North Country Radio posted by John Davis on August 13, 2013
Awesome. Thanxs. tower climbing video
Lee
Posted by Doug Williams KB4OER on August 18, 2013 at 17:03:11.
Amazing.
http://www.youtube.com/watch?v=2A_h2AjJaMw&feature=player_embedded
No amount of money could motivate me to do this.
Re: tower climbing video
Posted by Lee on August 19, 2013 at 05:02:12.
In reply to tower climbing video posted by Doug Williams KB4OER on August 18, 2013
Yikes. I've seen this one before. Makes me nasueous every time. To think I complained about the Air Force making me climb a 300 ft tower. Watering hole Hifers
Lee
Posted by Garry, K3SIW on August 21, 2013 at 16:31:19.
Hifers NC, EH, and USC are all coming in well at the hifer watering hole as local noon approaches here near Chicago.
73, Garry, K3SIW, EN52ta, Elgin, IL
Hifer Antennas
Posted by Brian on August 22, 2013 at 23:10:30.
I'd be interested to hear and see what antennas are being used for the Hifers. Also did the HF stick for 20 meters have to be modified to resonate at 13.555 mhz ? I'm hoping to have good reception reports from here in DN20 so any hints would be helpful !!! Also are any of the Medfers active ???
Re: Hifer Antennas
Posted by andy on August 23, 2013 at 00:58:58.
In reply to Hifer Antennas posted by Brian on August 22, 2013
Brian,
I'll look for your Hifer and let you know what I copy here in Maryland. I copy SIW almost daily and several others including EH when the conditions are good. SIW has been the most consistent and strongest Hifer copied here by far. I run an SDR-IQ receiver and Argo or QRSS VD Spectrograph nightly and most all day weekends (when thunderstorms are not threatening). I just wish there was a place here to post images of the Hifers I grab, the watering hole gets crowded at times with some impressive signals.
Andy Re: Hifer Antennas
Posted by John Davis on August 23, 2013 at 04:53:26.
In reply to Re: Hifer Antennas posted by andy on August 23, 2013
>>> I just wish there was a place here to post images of the Hifers I grab
Our Community Forum area is set up for that very purpose. It is different from this message board in that you have to register to be able to post there, but it does allow image uploads.
John
Re: Hifer Antennas
Posted by John Davis on August 23, 2013 at 05:00:00.
In reply to Hifer Antennas posted by Brian on August 22, 2013
Sadly, I have to assume from the longtime lack of updates from the operators that most MedFERs are not actually on any more.
As for HiFER antennas, simple is good, and IMHO, omnidirectional is best. Anything vertical that can be resonated over a good ground plane, and isn't too close to obstructions, will stand a reasonable chance of being heard. Some guys do use dipoles, but you sacrifice a certain percentage of your potential audience in the directions of the minima.
John
Re: Hifer Antennas
Posted by AndyD on August 23, 2013 at 18:03:54.
In reply to Re: Hifer Antennas posted by John Davis on August 23, 2013
John,
Thanks for the community link, can't believe I missed that one.
Brian,
If there's interest I would like to put the LoMedfer beacon I've been working on the air this winter. Antenna would be a magnetic loop in the attic. EH took his LoMedfer beacon off air due to lack of reports. I wouldn't mind trying my hand at it with a different antenna approach. Unfortunately, the very narrow beam width of the mag loop would limit me even more than a short dipole. I'll give it a shot anyway.
Andy Re: Hifer Antennas
Posted by Brian on August 24, 2013 at 12:13:18.
In reply to Re: Hifer Antennas posted by AndyD on August 23, 2013
Cool, I will definitely listen for it. I am new at this part15. QRP stuff but having fun already !!! Still looking to log my first lowfer !!!
Hifer PBJ back on from new QTH in TN
Posted by Chris Waldrup on August 24, 2013 at 20:25:32.
Hi,
I got Hifer PBJ back on the air this afternoon after a several year hiatus. I am operating from my new QTH in middle Tennessee.
The frequency is 13.557 Mhz and I am operating QRSS.
Reception reports appreciated!!
Re: Hifer Antennas
Chris
KD4PBJ
Tracy City, TN
Posted by Paul on August 25, 2013 at 17:32:55.
In reply to Hifer Antennas posted by Brian on August 22, 2013
HiFer FRC uses a "HamStick" 20m mobile antenna on a metal building (ground plane) on top of a high mountain. The antenna tunes perfectly to 13.565 MHz. with no modification necessary.
Considering it's running 10 WPM CW (not QRSS or any other weak signal mode), it gets heard very frequently. QSLs are received in the mail monthly.
Considered using a 1/4 wave vertical made of aluminum tubing at first. However, after making field strength measurements, it was determined that the field would be above the part 15 limit for the band segment, so a more simple and smaller antenna was installed. The HamStik has been up for many years now with no trouble, despite the high winds, hail, ice, etc. that site receives through the year.
Best of luck to you!
Re: Hifer PBJ back on from new QTH in TN
Posted by Paul on August 25, 2013 at 17:33:56.
In reply to Hifer PBJ back on from new QTH in TN posted by Chris Waldrup on August 24, 2013
I am QRV!
Daytime 72.4 kHz Reception
Posted by John Davis on August 25, 2013 at 21:04:26.
Stations of the new WG2XRS Experimental Service license have been doing the occasional daytime test. Dexter McIntyre (/5) was on from this morning into this afternoon with QRSS60, and as I write this, John Andrews (/3) is on with DFCW90 (also viewable with Argo) just below Dex's spot.
Today was the first chance I've had to look for them on groundwave at mid-day, and it was very productive. From Stanfield, NC, to southeast Kansas with solar noon directly between us at the start of capture, I'd say the copy was mighty solid considering the summertime static levels!
I hope to get back to the field and try for /3 myself shortly.
John
HiFERs Sunday & Monday
Posted by John Davis on August 27, 2013 at 18:39:12.
Went to the field three times Sunday...late morning for the daytime 72.4 kHz test, late afternoon, and again after dark. I did some HiFER monitoring the last two times, but the band was terrible. Only EH was visible Sunday afternoon, standing out rather conspicuously without anyone else around. During the evening session, it was accompanied by a faint trace from SIW slant mode, and briefly also by SIW QRSS6. Of the conventional CW signals, only FRC was audible. I got a good clear "K6FRC K6FRC" pair at 9:33 PM CDT before conditions deteriorated to a character here and a character there.
Monday evening, most everybody was back at the watering hole except SIW. USC was quite strong for a while, then faded to barely visible. EH was solid, it looked like MP was back but missing some dots and occaisonal bits of dashes as well, and NC was not super strong but pretty consistent. Audibly, FRC was quite solid by ear for several cycles in a row just before 10 PM.
John
WG2XCT CW Beacon on 475.1 kHz
Posted by John Davis on August 28, 2013 at 04:04:47.
My later start time tonight resulted in somewhat fewer bugs but no less lightning static, apparently. Another continuous roar.
When I first got to the field around 9:30 PM CDT, I couldn't hear anything at all from XCT or even see a trace on Argo at QRSS3. I diverted my attention to HF for a little while, where codar was blasting away fiercely, but I could still see USC, SIW slant mode, and NC, with the occasional trace of EH. Higher up, FRC was not as plagued by codar, and was coming through moderately well with several complete IDs.
Returning to 475.1 around 10 PM, I did see a trace of Pat's signal right on 475.100 and could hear keying faintly.
There was at least no significant interference tonight from WD2XSH/6 at 475.320, in a combination of CW and QRSS3. Even though I was able to adjust my passband to put XSH/6 far enough down the slope to fall below audibility, Argo was still able to bring it up readably on a second screen.
Pretty soon, XCT began creeping up in level. At its peak, around 10:12 CDT, I could copy two and three characters at a time. A "WG2" here and a "G2X" there were pretty convincing to me, at least. The level dwindled after that, but seemed to be returning gradually again by the time I had to quit at 10:20.
With an S-unit little less QRN, I think copy would be quite solid.
John Re: WG2XCT CW Beacon on 475.1 kHz
Posted by SalK1RGO on August 28, 2013 at 14:15:47.
In reply to WG2XCT CW Beacon on 475.1 kHz posted by John Davis on August 28, 2013
John, HiFER's Tuesday night 8/27
Do you have any info when 630 meters will become a ham band and what modes will be the rule? I have a rig built and ready to go.
later, Sal...............
Posted by Bob WA1EDJ on August 28, 2013 at 14:42:50.
EH almost every night, audible strong. NC square wave, 6:00 PM Eastern good short skip I think. First copy for NC.
Other nights recently......MP, SIW ramp and CW. Occasional USC around 7:00 PM. Re: WG2XCT CW Beacon on 475.1 kHz
EDJ will continue to be QRV on weekends. Fewer TS lately....Bob....EDJ....
Posted by John Davis on August 28, 2013 at 17:01:30.
In reply to Re: WG2XCT CW Beacon on 475.1 kHz posted by SalK1RGO on August 28, 2013
Sorry, Sal, no action is yet even contemplated by the FCC. As with everything else lately, Canada will have it before we do.
Like everyone else in government right now, the Commission has got to do what they can under the current "forced diet." At a time when even the Air Force has to shut down rather important things like the Space Surveillance Radar that protects us all, creating new regulations to benefit a relative few amateurs is a low priority.
John
Re: WG2XCT CW Beacon on 475.1 kHz
Posted by Pat Bunn on August 28, 2013 at 18:01:20.
In reply to WG2XCT CW Beacon on 475.1 kHz posted by John Davis on August 28, 2013
WG2XCT will be transmitting QRSS3 on 475.1 KHz today and through the night.
Reports are appreciated.
Pat Re: WG2XCT CW Beacon on 475.1 kHz
N4LTA
Posted by Pat Bunn on August 29, 2013 at 23:53:31.
In reply to Re: WG2XCT CW Beacon on 475.1 kHz posted by Pat Bunn (Fwd) on August 28, 2013
John,
I am going to leave it on continuously until I leave for the coast on Friday afternoon.
Thanks everyone for the reports. The transmitter is running at approximately 500 watts output.
Pat
WG2XCT
Re: WG2XCT CW Beacon on 475.1 kHz
Posted by Sal, K1RGO on August 30, 2013 at 01:08:13.
In reply to Re: WG2XCT CW Beacon on 475.1 kHz posted by John Davis on August 28, 2013
I guess I'll be QRT on 630. I'll give a listen to the part 5ers for now..........
later, Sal
potrzebie