regen preamp question?
hello
does anyone have a copy of the discription and schematic for the regenerative preamp described in the 9th ed of ken cornell's scrap book?
thanks dave
Re: Looking For Simple HiFER Schematic
Posted by Paul on October 01, 2009 at 12:38:24.
In reply to Re: Looking For Simple HiFER Schematic posted by KCØW on September 06, 2009
Hi Tom.
Still haven't heard from you. Do you still want the HiFer transmitter? It's ready to go when you are.
73,
Paul
"PBO" 187.2 khz off for a few days
Posted by Rick KA2PBO PBO on October 01, 2009 at 16:50:29.
Hi all
PBO will be silent for a few days for maintenance. Will announce when I fire up again
FOR SALE SIERRA 303A SLM
Thanks
Rick
KA2PBO "PBO" 187.2 khz QRSS20
Posted by AL on October 02, 2009 at 10:41:06.
For those that don't know this unit covers 0 hz thru 3500khz. It has digital readout,attenuator etc and works very well but is now excess to my needs.
$100 and ship from Central Florida or meet you somewhere if you desire to pick up.
Pix sent on request.
I am in Central Fla near Orlando.
Thank you Re: Loading coil changes "JAM" 188khz
Al
Posted by Lee - Beacon - JAM on October 02, 2009 at 16:26:12.
In reply to Re: Loading coil changes "JAM" 188khz posted by Peter B on September 30, 2009
Thanks Peter for the K1EL tip. Procrastination pays off again for me. I will be buying the K1EL product.
Re: regen preamp question?
Posted by Steve on October 02, 2009 at 19:53:47.
In reply to regen preamp question? posted by dave sampson on October 01, 2009
Hi Dave - I have a copy of the 6th edition that describes Ken's regen preamp. I'd be happy to email you a PDF of that section - just let me know your email address. Tnx - Steve KC0YA Beacon XR in the watering hole
Posted by Andy - XR on October 02, 2009 at 20:19:10.
" XR " is on 185,298.55 KHz, QRSS-60, Any reports appreciated.
73 :::
Andy - Beacon " XR " Friendsville, TN. EM75xr
Beacon "JAM" 188khz On Air
Posted by Lee - JAM - 188khz on October 03, 2009 at 01:57:35.
On the air this weekend. Until it rains. We are not water proof yet.
Grid square DM04uf La Crescenta, LA County. Testing with CW now and code later when I buy a memory keyer. Any reception reports welcome. For records/logging purposes you can call this LowFER "JAM". 188 KHZ. This beacon will be on the air most weekends if I'm not working and intermit weekdays.
Thanks
Lee
Re: Beacon "JAM" 188khz On Air
Posted by Mark on October 03, 2009 at 08:59:52.
In reply to Beacon "JAM" 188khz On Air posted by Lee - JAM - 188khz on October 03, 2009
I will look for your signal tonight and tomorrow morning!
73, Mark, Ku7z Beacon DIR on the air...
DN41af
Ogden, Northern UT (NUT)
Posted by Jim W4JBM on October 03, 2009 at 09:20:52.
I've finally got DIR up and running. I'm using a PIC based keyer to send QRSS-30. The oscillator is a crystal controlled VXO set to 172.945 kHz (as close as I can measure with the gear I have). Actually the VXO is set to twice that and then it's divided by two in a line driver to make sure I've got a clean square wave going out on the coax. The final is a slightly modified LEK design. It's operating at 11 volts and pulling 9 mA (measured at the xmitter).
Antenna is a 30 foot high T configuration with the upper portion also being 30 feet. For now it's held in place with a pair of fence t-posts I've driven and lashed army surplus tent poles to to get it up in the air.
Location is Bowdon Junction, GA (33.6581,-85.1249 EM73). If anyone receives it, I'd love to see screen shots and I will QSL.
Hopefully will be able to move the frequency closer to the watering hole in the next few weeks and also want to build a better "top hat" for the antenna.
73 de Re: Hifer SZX
Jim W4JBM
Posted by Mark Garrett on October 03, 2009 at 10:14:33.
In reply to Hifer SZX posted by Sal, K1RGO on September 30, 2009
Hi Sal:
You are the second person to hear this beacon. Nice to know it is radiating enough to be heard. Using a Parallax Experimenter board with a PIC16F57 stamp driving an Epson osc. "PBO" back on the air 187.2khz
Still sitting open on the bench feeding a delta loop and a Vanco SWR-4 Meter and antenna match unit near Macomb, IL.
Let me know if you hear it again.
Posted by Rick KA2PBO on October 03, 2009 at 10:45:29.
PBO is back on 187.2 khz running QRSS 20
Thanks Re: FOR SALE SIERRA 303A SLM
Rick
Posted by Jim Vander Maaten on October 03, 2009 at 11:03:08.
In reply to FOR SALE SIERRA 303A SLM posted by AL on October 02, 2009
Good luck Al, I have been trying to sell my Sierra 303B for
$40.00 at flea markets for some time. I even have the service
manual. Good receiver, 80 Hertz filter and all. The lead acid batteries are long gone though.
73 jim wb6qzl Re: Beacon DIR on the air...
Posted by Jim W4JBM on October 03, 2009 at 14:35:06.
In reply to Beacon DIR on the air... posted by Jim W4JBM on October 03, 2009
After some changes and figuring out I was doing some math wrong, DIR is pulling at just around 1 watt input with 13.7 volts and 70 mA.
73 de Re: Beacon DIR on the air...
Jim W4JBM
Posted by Jim W4JBM on October 04, 2009 at 04:17:23.
In reply to Beacon DIR on the air... posted by Jim W4JBM on October 03, 2009
The keyer had locked up and I was transmitting a solid carrier from sometime after 2100z yesterday evening. Not sure exactly when it locked, but I reset it this morning at 1100z.
Right now the plan is to keep DIR running through mid-day Monday.
73, Re: VLF BOATANCHOR SALE/TRADE UPDATE INFO.
Jim W4JBM
Posted by Emmanuel Gauquelin on October 04, 2009 at 11:55:50.
In reply to VLF BOATANCHOR SALE/TRADE UPDATE INFO. posted by dave sampson on August 12, 2009
dear Sir,
I am swl vlf and elf a, i am interested by this vlf receptor, but i would like to know the price.
I live in France.
thanks.
73's Emmanuel
Re: Beacon DIR off the air...
Posted by Jim W4JBM on October 05, 2009 at 04:14:19.
In reply to Beacon DIR on the air... posted by Jim W4JBM on October 03, 2009
Because I'm traveling out of town, I will be taking DIR off the air for the week. The plan right now is to bring it back on next Friday afternoon.
Thanks to all who gave a listen for it.
73, Beacon XR moves to the watering hole
Jim W4JBM
Posted by Andy - XR on October 05, 2009 at 11:59:43.
Hi All:
Beacon - XR can now be found by looking slightly below 185.299 KHz in QRSS-60 window. I hope to get some confirmed captures this season on the new frequency. I do card QSL every confirmed reception report I get, even the guys who already have one from the former frequency.
73 ::: Andy - Beacon - XR
Re: Beacon DIR on the air...
Posted by John Hoopes on October 06, 2009 at 09:50:48.
In reply to Beacon DIR on the air... posted by Jim W4JBM on October 03, 2009
You're about 100 miles from me as a crow flys so I'll take a listen.
John
LowFER Beacon CV
Posted by Charlie Vest on October 06, 2009 at 18:41:23.
CV , is back on the air on 185.29825 kHz. , QRSS60 ,24/7 , EM26ex , OK. ,
Parts on order for a MedFER beacon , for this season , which should be on in a couple of weeks .
Charlie , W5COV
Watering hole
Posted by Roger on October 07, 2009 at 05:22:53.
Captures of the watering hole overnight revealed one signal. MP was coming in between 2 and 5 am. Will be looking for others. DIR on the air
Roger, Beacon RM 189.8
Posted by Jim W4JBM on October 08, 2009 at 12:07:33.
DIR is on the air at around 172.945 kHz. I'm working on getting it moved towards the watering hole but it will probably be a couple of weeks. I plan to make some minor antenna changes during the day on Saturday.
73, Re: ESA HiFer Beacon active from new QTH
Jim W4JBM
Posted by Jim Vander Maaten on October 09, 2009 at 09:57:35.
In reply to ESA HiFer Beacon active from new QTH posted by Jim Vander Maaten on September 27, 2009
No reports of reception so ESA beacon is off.
Will try again using different antenna.
jim vm Beacon "JAM" 188khz on air
Posted by Lee - JAM - 188khz on October 09, 2009 at 16:45:43.
No keyer yet.
Grid square DM04uf La Crescenta, LA County. Testing with CW now and code later when I buy a memory keyer. Any reception reports welcome. For records/logging purposes you can call this LowFER "JAM". 188 KHZ. This beacon will be on the air most weekends if I'm not working and intermit weekdays.
Thanks
Lee
Re: DIR on the air
Posted by Jim W4JBM on October 10, 2009 at 09:20:25.
In reply to DIR on the air posted by Jim W4JBM on October 08, 2009
Made some tweaks to the antenna this morning and have about 18 dB higher field strength than I did last week. Hopefully it's pushing out a bit further. Still no confirmed reports.
A centuary of Nobel Prize for Braun & Marconi
Posted by Juergen / DL8HCI on October 11, 2009 at 02:51:18.
On pre Nobel Prize day, 9th December 2009 23:00 UTC until 10th December 2009 01:00 UTC National Weather Service longwave transmitter DDH47 on 147,3 kHz at Re: Beacon "JAM" 188khz on air
20 kWatts will held a memorial telegraphy broadcast. Radio amateurs may contact
DL0PFB / DDH47 on hf bands. Extreme slow keying qrs3 will take place during the
former silence periods in maritime service ( hour 15-18 and 45-48). Further infos
on internet: www.mmqtc-award.org link Nobel Prize - Juergen / dl8hci manager of
Prof. Braun Days / DL0PFB
Posted by Mark - Ku7z on October 11, 2009 at 07:57:39.
In reply to Beacon "JAM" 188khz on air posted by Lee - JAM - 188khz on October 09, 2009
Lee, I have listened but no luck yet.
73, Mark NDBChange(B)log
Ogden, Northern UT (NUT)
Posted by Michael Oexner on October 11, 2009 at 09:05:34.
Hi all,
If you're interested in receiving news on NDB changes, new NDBs, deletions etc. please follow my blog at
http://ndbchangeblog.blogspot.com
You can also sign up there to receive e-mail notifications when the blog is being updated.
__
vy 73 + gd DX,
Michael
ENDBH & NANDBH editor
http://ndbchangeblog.blogspot.com Latest US NDB deletions
Posted by Michael Oexner on October 11, 2009 at 09:07:40.
Hi all,
The following deletions have been announced effective 2009-10-22:
AIO-365.0 Atlantic IA last log rww 2008-07-26
AOV-341.0 Ava/Bilmart MO last log rww 2007-01-16
HHY-346.0 Savannah/Pinhook TN last log rww 2009-03-06
HNR-272.0 Harlan IA last log rww 2009-06-21
JZI-283.0 Charleston/Johns Island SC last log rww 2008-12-05
MHA-364.0 Manitowish Waters WI last log rww 2009-05-24
--
vy 73 + gd DX,
Michael
ENDBH & NANDBH editor
http://ndbchangeblog.blogspot.com
Re: DIR is OFF the air
Posted by Jim W4JBM on October 12, 2009 at 03:31:14.
In reply to DIR on the air posted by Jim W4JBM on October 08, 2009
Lost the final overnight. Hope to have it back up and near the watering hole in the next few weeks.
73, Re: Beacon "JAM" 188khz on air
Jim W4JBM
Posted by Lee - JAM - 188khz on October 12, 2009 at 16:28:17.
In reply to Re: Beacon "JAM" 188khz on air posted by Mark - Ku7z on October 11, 2009
Great! Good to know someone is listening. Because of my location orientation I should have a very good shot eastward.
73 Lee
Hifer update
Posted by Sal, K1RGO on October 13, 2009 at 11:08:54.
It seems like the band is improving lately. Today (10/13) I copied in the time frame of 17:00 to 17:30 UTC, HI ,529 on 13.557,an unknown on 13.560, 539 wid QSB sending dots at 3Hz, and again SZX on 13.563 peaking 549 wid QSB. also noted but not in there for long, a partial ID with a chirpy note possibly sending A? W? ..... My EH on ~13.557 is still on 24/7.....only off with listening breaks. Best portable for LW dx.
Later.....Sal K1RGO
Posted by john on October 15, 2009 at 20:13:56.
whats the best small portable on the market for LW dxin? in the past i have owned the sony 2010, degan 1103 and eton e1. the eton was awesome on lW, but its big radio, almost table top size and i would like something smaller. the 2010 while a great am BCB dx'er, was weak below 540 khz as was the degan. appreciate all opinions. thx, john
Beacon "JAM" 188khz on air
Posted by Lee - JAM - 188khz on October 16, 2009 at 18:37:26.
No keyer yet. JAM will be up and down a few times for work during the day Sat 10/17.
73 Lee
Denmark Kalundborg 243 kHz reactivated
Posted by Mike Terry on October 17, 2009 at 05:45:17.
Surprisingly Kalundborg 243 kHz longwave was on air briefly October 15th at 09:00-09:10 AM local with same program as mediumwave 1062 kHz (Radioavisen/News) and full power, otherwise it has sent DRM with 0.2 kW since 3 October 2008.
From October 16th and until end of the month Danmarks Radio's longwave 243 kHz AM Kalundborg will take over three of the daily programs, normally sent via 1062 kHz:
243 kHz
05:35-06:13
05:45-05:51 Weather
06:00-06:07 News (Radioavisen) // with P4
11:35-12:36
11:45-12:00 Weather
12:00-12:30 News (Radioavisen) // with P4
17:35-18:26
17:45-18:00 Weather
18:00-18:16 Announcements from the (Navy Operational Command)
1062 kHz
08:25-09:13
08:30-08:40 Gymnastics
08.45-09.00 Weather
09:00-09:07 News (Radioavisen) // with P4
First 5-10 minutes and last 6-10 minutes of transmission an active carrier is on. "PBO" now running QRSS 60
Time is local = UTC+2 until 24/10, UTC+1 from 25/10.
Listeners' reports can be sent to info at bsd . dk
73s Ydun Ritz
(DXLD)
Posted by Rick KA2PBO on October 17, 2009 at 07:26:03.
i had a few requests to slow down my tx so Im sending at 60 sec dots now.
Thanks
Rick
Re: Denmark Kalundborg 243 kHz reactivated
" PBO" 187.2 khz / QRSS 60
Posted by Mike Terry on October 17, 2009 at 08:27:31.
In reply to Denmark Kalundborg 243 kHz reactivated posted by Mike Terry on October 17, 2009
A further update on DXLD:
Translated from a message in DR: Even greater DX on 500kHz QRPp WSPR - 896kms!
"For technical reasons [unknown], DR is forced from 16 October 2009 through the rest of the month to broadcast Notices to Seafarers only once every 24 hours on mediumwaves 1062 kHz. The remaining programmes will be broadcast via the longwave transmitter on 243 kHz. The mediumwave broadcast is transmitted from 8:25 to 9;13 (local time) each morning."
73, Ydun
Posted by Mike Terry on October 18, 2009 at 00:19:37.
17 October 2009
This is getting unbelievable now with such low power and a simple antenna: having just got a report from OR7T I've just now got one at -26dB S/N from GM4SLV in the Shetland Is all of 896kms away! This has been one of the best days ever in my ham radio life.
Roger G3XBM
http://g3xbm-qrp.blogspot.com/search/label/500kHz
Cornell's 'Low and Medium RF Scrapbook' on eBay
Posted by Steve KC0YA on October 18, 2009 at 18:18:25.
All - There is a copy of Ken Cornell's 10ed (final edition) 'Low and Medium Radio Frequency Scrapbook' on eBay. Item number: 130337392913 - auction expires Wed 21 Oct 2009 at 14:49:19 PDT. Shipping costs are quite reasonable ($3.00 to US), and the seller is top rated. These Scrapbooks are getting difficult to find. Re: Cornell's 'Low and Medium RF Scrapbook' on eBay
Posted by Don Moth W2MPK on October 21, 2009 at 16:38:05.
In reply to Cornell's 'Low and Medium RF Scrapbook' on eBay posted by Steve KC0YA on October 18, 2009
The scrapbook sold for $49.50.
best up converters
Posted by john on October 21, 2009 at 16:48:04.
wondering what the best VLF converter is. palomar, heathkit, datong and a few others make them. can anyone recommend one. also how do they compare with lets say a dedicated receiver on LW such as an icom r75. any info is appreciated.
Re: best up converters
Posted by John Davis on October 21, 2009 at 20:31:12.
In reply to best up converters posted by john on October 21, 2009
Heathkit??? Last I knew, they'd closed down kits entirely and were concentrating on the education market.
The question of upconverters, versus receivers already covering the LF region, obviously depends a lot on the quality of the individual product.
Most common upconverter kits do not employ particularly stable oscillators... entirely fine for NDB DXing, but not so great for very narrow bandwidth modes. I also have my doubts about the overload and IM properties of those employing certain IC mixers. Apart from those two drawbacks, upconverters have the potential to offer significantly greater sensitivity than most general purpose receivers are willing to give you by themselves below 500 kHz.
If you were to build your own upconverter around a very stable oscillator (temperature compensated or ovenized) and use a robust double-balanced mixer module ahead of most decent SW receivers, you could achieve performance very close to special-purpose LF receivers. One such design was written up in The LOWDOWN by Tim Brannon. You can find it in our library here: KF5CQ. It was published some time back, so I could not address parts availability these days, and I'm sure Tim's e-mail address given in the article is no longer operational. However, it remains a good design example.
I don't believe the Palomar quite equals its performance, though the Datong might come closer. I'll have to leave it to someone who has used both of them more than I have to advise you on their suitability. I can say with some confidence that cheaper upconverters, like Ramsey kits and similar efforts, do not compare.
As for communication receivers with LF coverage, it is interesting that you should mention the ICOM IC-R75. John Reed has done a thorough test of its performance at LF, scheduled to be published in the November issue of The LOWDOWN. I can only give you a hint here, but perhaps it will be helpful. Like most consumer receivers with LF coverage, the R75 is halfway deaf at lower frequencies by default, but unlike many, its built-in preamplifiers do actually help. It's got good frequency stability, an excellent noise blanker, and 1 Hz tuning resolution, all of which are very worthwhile at LF. The principal downside is the presence of an awful lot of spurs at the lower frequencies, specifically around 130 kHz and below. But if your work is mainly above that point, it looks to be a decent receiver at a reasonable price, without much (if any) external help required.
John
Lowpass filter cutoff point for longwave reception
Posted by Ken on October 23, 2009 at 10:45:09.
I am trying to decide between two Kiwa Longwave lowpass filter models - the 500 or 400 Khz (cutoff) lowpass. If I bought the 400 Khz cutoff (meaning signals above 400 would be filtered) what could I be missing?
In other words, today, what stations & signals are in the 400 to 500 Khz area? Thanks, Kebb
Re: Lowpass filter cutoff point for longwave reception
Posted by Andy - KU4XR on October 23, 2009 at 13:38:31.
In reply to Lowpass filter cutoff point for longwave reception posted by Ken on October 23, 2009
Hello Ken: Not knowing your listening interests, ie: NDB , LW broadcasters, experimental signals, and so on; unless you live a couple of miles from a high powered broadcast station in the low part of the band, the 500 KHz filter will probably do what you want. Are you a Ham Operator ? The 600 meter band from 490 to 515 KHz is very active with Experimental Stations right now using CW, WSPR, PSK, signals. It is hoped that the 600 meter frequencies will be authorized for Amateur use worldwide during the next conference in 2012. Secondly; if you are a little technically inclined, before you spend a bunch of money; try making your own filter using Inductors, and capacitors.
It's not very difficult to do, and here is a link to a great online calculator to help you calculate the values needed for your filter:::
http://www.calculatoredge.com/electronics/bw%20pi%20low%20pass.htm
http://www.calculatoredge.com/electronics/bw%20tee%20low%20pass.htm
Copy and paste into your browser address bar and play around with the calculators, they do the math for you. The first one is for a " PI " filter, and the second one is for a " TEE " filter. Both will do the same job for you.
Good luck, and have fun. 73 ::: Andy - KU4XR
Beacon "JAM" 188khz on air
Posted by Lee - JAM - 188khz on October 23, 2009 at 16:53:59.
No keyer yet. It will be on till Tuesday morning 10/27/09 weather permiting. Grid square DM04uf La Crescenta, LA County.
73 Lee
Re: Best portable for LW dx.
Posted by Paul on October 23, 2009 at 21:18:37.
In reply to Best portable for LW dx. posted by john on October 15, 2009
I use a Grundig YB400, and it works amazing on LW. But frequency range is a little limited.
Works awesome on HiFer band too.
__________________________________________
"whats the best small portable on the market for LW dxin? in the past i have owned the sony 2010, degan 1103 and eton e1. the eton was awesome on lW, but its big radio, almost table top size and i would like something smaller. the 2010 while a great am BCB dx'er, was weak below 540 khz as was the degan. appreciate all opinions. thx, john " SMV Lowfer Copied
Posted by Mark on October 24, 2009 at 06:44:30.
While looking for JAM this morning I was lured down to SMV's freq by an email about Calif beacons and found it! First time I have logged it here.
20091024 1115utc 186.583 SMV CW ident
Mark, Ku7z Beacon " XR " new station photos
DN41af
Ogden, Northern UT (NUT)
Posted by Andy - XR on October 24, 2009 at 23:27:45.
Hi all:
I snapped a few photos of the current Beacon " XR " equipment. They are posted in the station pictures on My Space
73 :::
Re: SMV Lowfer Copied
Andy - KU4XR - EM75xr - Friendsville, TN.
LOWfer Beacon " XR " @ 185.29893 KHz ( QRSS-60 )
Coordinates: N: 35* 43' 54" - W: 84* 3' 16"
http://www.myspace.com/beaconxr
Posted by Lee on October 25, 2009 at 00:01:43.
In reply to SMV Lowfer Copied posted by Mark on October 24, 2009
Mark give 183.45khz a try. That is WD2XFJ [formerly PLI]. He is in Burbank CA. Just a couple of miles from JAM and about 30 mile from SMV. It would be good info for me if you can copy WD2XFJ.
73 Lee
Reactivation of Kalundborg 243 kHz
Posted by Mike Terry on October 25, 2009 at 10:15:50.
The reason for the reactivation of Kalundborg 243 kHz is work in the harbour. Huge wind mills to be placed in the Great Belt have to be assembled by means of a big crane. This crane get "electric" from interference caused by the mediumwave transmitter of 1062 kHz. During the MW transmission at 0735 UTC in the morning work with the crane is paused.
In Danish: http://www.nordvestnyt.dk/artikel/45102:Kalundborg--DR-s-vejrudsigt-goer-kran-elektrisk
(DXLD)
HiFer NDB Changes
Posted by Jeff K8NDB on October 25, 2009 at 11:59:37.
Hi Gang,
I have made some changes to my HiFer beacon NDB as follows:
FREQ 13.562020 MHz
PWR 4.0 mW
ANT 1/4 Wave Vertical/Metal Roof Ground Plane
ID NDB 10 WPM CW, AZ QRSS-3
If anyone should copy it I would appreciate a signal report/capture.
Thanks and 73,
Jeff K8NDB DIR back on air
Yuma, AZ
Posted by Jim W4JBM on October 25, 2009 at 12:12:02.
DIR is back on the air. Still some things on the to-do list, but I'd appreciate any reports. DIR is at around 172.945 kHz +/- a bit and keying at QRSS-30.
Next project is to finish the divider that will let me move up to the watering hole frequency. But this is all I've got time for right now.
73 de
Jim W4JBM
Location - Bowdon Junction, GA USA (33.6581,-85.1249 EM73)
http://www.hamuniverse.com/w4jbm/
"With a soldering iron in one hand, a schematic in the other, and a puzzled look on his face..."
Working the world from the New Dog Iron Ranch!
Re: Beacon "JAM" 188khz on air
Posted by Lee - JAM - 188khz on October 25, 2009 at 15:16:48.
In reply to Beacon "JAM" 188khz on air posted by Lee - JAM - 188khz on October 23, 2009
I addressed some lossy antenna issues I noted after reading an article from the lowfer heyday of the mid 80's. Good thing I wasn't being graded for this antenna! Also I was able to get the skirt wires a little higher in the air today. I will be installing a more robust base insulator during the week. Thanks to all who gave it a listen.
73 Lee
Re: best up converters
Posted by Todd WD4NGG on October 25, 2009 at 16:09:15.
In reply to Re: best up converters posted by John Davis on October 21, 2009
I would like to add that in my experience in most cases a good LF/VLF up converter in front of an already good general coverage communications receiver almost always does better than the receiver by itself especially if you desire to listen to the VLF range below 30KHz.
Many good communications receivers, including ones like the Harris RF-590 that include coverage below 30KHz, have degraded specs once you get much below about 60KHz or so. Many other good receivers stop at 100KHz and some even stop at 500KHz.
I have had very good results with a homebuilt AMRAD clone converter I made using a 3MHx OCXO for the local oscillator. The OCXO is stable well within 1Hz after a 15-20 minute warmup and preserves the frequency accuracy of an already good receiver with 1Hz readout. It is stable enough for QRSS service as long as the receiver is also stable well within 1Hz.
The AMRAD converter with 3MHz OCXO converts the 0-500KHz range up to the 3.0-3.5MHz range where most general-coverage receivers already have excellent sensitivity and specs. A good 500KHz lowpass filter is recommended in front of the converter to cutoff possible interference and overload from the broadcast band frequencies and higher. Some shortwave and broadcast band signals are extremely strong and can produce images if a good 500KHz lowpass filter is not used.
My favorite LF/VLF listening setup is the Icom R75 with CR-282 high-stability OCXO, matching 250Hz CW filters in the 9MHz and 455KHz IFs, a Steve Ratzlaff active whip mounted high and in the clear and a homebrew 500KHz lowpass filter in front of a homebuilt AMRAD clone converter with 3MHz OCXO.
73 Todd WD4NGG
Spectrum Lab v 2.2
Posted by Rick KA2PBO on October 25, 2009 at 18:23:21.
Does anyone have a copy of Spectrum Lab v2.2 or earlier? I have the new v2.7.I am using Lyles software/ downconverter setup but I cant get it working right with the new version.Too many bells and whistles.
Thanks
Rick KA2PBO
"PBO" 187.2 QRSS/60
Re: Lowpass filter cutoff point for longwave reception
Posted by Jim W4JBM on October 26, 2009 at 10:09:22.
In reply to Lowpass filter cutoff point for longwave reception posted by Ken on October 23, 2009
Steve Ratzlaff made the LF modification to my Ten Tec RX320 for me. There were a couple of LPFs that I considered, but the one I ended up with is one Steve pointed me towards at:
http://www.qrp.pops.net/ndb_more.asp
I can see roll-off beginning at about 500 kHz on the one I built and that works good--the only two local "power houses" (I live about an hour outside of Atlanta) are up above 1,000 kHz, so they are well filtered.
I'm too cheap to buy parts, so I ended up using some old BCB IF transformer's to build my inductors and used capacitors I had laying around.
There are some NDBs and the ham radio LF testing around 500 kHz. But the bottom line really is that even at those frequencies you're typically more limited by the noise floor than receiver sensitivity.
73, Re: DIR back on air
Jim W4JBM
Posted by Jim W4JBM on October 28, 2009 at 07:39:53.
In reply to DIR back on air posted by Jim W4JBM on October 25, 2009
I still haven't had any reception reports to this point. I would appreciate any reports of "failed attempts" at listening. At this point I'm not sure how well I'm getting out. I've played with the antenna and the tuning system and my near field measurements have gone up significantly.
But I may still just not be making it out. In that case I might have to rethink my antenna placement.
73, HI-510.145khz
Jim W4JBM
Posted by Vernon Matheson - VE1VDM on October 28, 2009 at 15:23:05.
Very good copy on October 26 @ 2255utc....
Any information as to output etc...id Monroe CT the transmitter location?
Best regards,
Vernon - VE1VDM
Onslow, Nova Scotia
Canada
FN85ij
Re: HI-510.145khz
Posted by John Davis on October 28, 2009 at 20:33:36.
In reply to HI-510.145khz posted by Vernon Matheson - VE1VDM on October 28, 2009
You'd have to write to the operator for that information. And I mean, literally, write. He has no e-mail.
YouTube - DXing the longwave band
Posted by Mike Terry on October 29, 2009 at 09:32:12.
Interesting new video from K9RZZ, one for the techies
http://www.youtube.com/watch?v=MQIGNh7bf3o
Re: OM-320 off the air in Omaha
Posted by Barry on October 29, 2009 at 19:35:48.
In reply to Re: OM-320 off the air in Omaha posted by Barry on September 07, 2009
Both NDBs (OM and EN) are now back on the air. Beacon "JAM" 188khz on air
-Barry
Posted by Lee - JAM - 188khz on October 29, 2009 at 19:44:21.
No keyer yet. It will be on till Tuesday morning 11/03/09 weather permiting. Grid square DM04uf La Crescenta, LA County. Now with confirmed large antenna current!
Re: YouTube - DXing the longwave band
Posted by Andy - XR on October 30, 2009 at 13:39:13.
In reply to YouTube - DXing the longwave band posted by Mike Terry on October 29, 2009
Pretty nice video. and links to other LF videos
"GNB" on the air
Posted by Gary Babcock GNB on October 30, 2009 at 20:55:54.
Re: "GNB" on the air
the LOWFER beacon "GNB" is on the air at 188kc. Running One watt to a 45ft groundplane. Location is DM73vb in Hagerman, New Mexico
Posted by John Davis on October 31, 2009 at 11:43:29.
In reply to "GNB" on the air posted by Gary Babcock GNB on October 30, 2009
What mode, please?
Re: "GNB" on the air
Posted by Gary Babcock on October 31, 2009 at 14:04:58.
In reply to Re: "GNB" on the air posted by John Davis on October 31, 2009
Mode is CW at 5wpm repeating "GNB" we are on 24/7
potrzebie