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Author Topic: 630 meters  (Read 39814 times)
K4EJQ
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Posts: 100




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« Reply #60 on: March 18, 2013, 09:27:31 PM »

Andrew et al; FYI-Just finished the spectrural tests on the new 630 Mtr 3-1000Z amp I mentioned above. With 30 watts of driving power, 1000 watts DC input-2500 Vdc @ 400Ma.plate current, power output measured 600 watts. All spurious signals were measured at -45dbc or less . NO external rf filtering used. Now, if I can do as good on the rest of the bands this thing covers, Hi.

Have fun-always!!  73, Bunky, K4EJQ ( in the annexe )
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GW3OQK
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« Reply #61 on: March 19, 2013, 02:18:17 AM »

The pictures you sent show it as a good homebrew PA Bunky. Whats the PSU like? You should get many amps of RF into your aerial with that. Excuse my ignorance but is the band in use now in North America with 5w eirp as it is in EU? I suppose some day there will be a transatlantic qso.
73
Andrew   
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K4EJQ
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« Reply #62 on: March 19, 2013, 01:37:34 PM »

Hello Andy et al; The PSU is actually built-in the amplifier. I will try and get you a pix showing the plate xfmr/supply. The  HV filter cap bank as well as the bleeder resistors is under the chassis in the "pressurised" area where there is cooling airflow from the muffin fan.  The fan which is mounted on the chassis bottom plate pulls in cooling air from outside the unit and forces it up through the PA tube's air-system socket located directly above it. Even at full power input (1500 watts or so ) the amplifier runs cool. It also will heat my ham shack in winter when I'm banging away on 160 meter CW-"Hello World"-HI.

In addition, all RF in/out switching and VOX circuitry are included within the amplifier-The amp is wired for 120 VAC primary so I can use it anywhere in the shack. The filament transformer for the tube as well as the low voltage dc control voltage power supply also included in the amplifier.  My shack has the AC power distribution box in it, so short heavy duty power wiring keeps the AC voltage pretty much constant with Waring loads.

At this writing, I have no idea when we US hams will get the new band. From what I hear on the bands there are several different groups of experimental stations. Some run low power on just a few frequencies while others , using many different modes including SSB, can operate over a much wider frequency range with considerable power output. What we US hams get is still "up in the air" so to speak. At the speed this process is moving, it will be next winter before we shall be able to use the band. I too, am looking forward to that day.

Have fun in the annexe. Keep the soldering iron warm!!!!

73, Bunky, K4EJQ ( in the basement)
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K0OD
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« Reply #63 on: March 20, 2013, 01:56:28 PM »

630 Meter Band Mis-routed!

"WRC-12 MF Allocation: In November 2012, the ARRL filed a Petition for Rulemaking with the FCC seeking domestic implementation of the international amateur allocation at 472-479 kHz. The Petition was mistakenly misrouted by the Office of the Secretary to the Mass Media Bureau. After repeated requests over a period of three months, the Petition is now with the Office of Engineering and Technology."

http://www.arrl.org/news/arrl-executive-committee-focused-on-fcc-and-regulatory-items-at-march-meeting
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K4EJQ
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« Reply #64 on: March 20, 2013, 07:43:40 PM »

K0OD: Thanks OM for the update on the proposal for 630 meters. It's always something , especially when your "chomping at the bit" to play with something new.
Enjoying myself with homebrewed projects for this new band and awaiting better weather in which to play outside with the other kids my age, Hi. 73, Bunky, K4EJQ
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AC2EU
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Posts: 392


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« Reply #65 on: March 21, 2013, 09:02:52 AM »

When is there anything on 630M? I heard NADA!
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W4OP
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« Reply #66 on: March 21, 2013, 10:18:49 AM »

When is there anything on 630M? I heard NADA!

What is your rx setup?

Dale W4OP
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K0OD
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« Reply #67 on: March 21, 2013, 12:27:36 PM »

Conditions have been poor the last few days, but I can usually pick up a few experimenter beacons around 475.0 KHz. Many only transmit in the evening and use Morse or PSK. Some use QRSS. Phone is very rare.

At my St Louis QTH the loudest station is usually WD2XSH/7 in Louisiana on 476.3 which alternates between CW and PSK. I use a normal ham HF vertical into a Flex-5000/Palomar converter. I can also hear ham beacons on my Kenwood TS-850 and TS-430 which have pretty decent longwave reception.

« Last Edit: March 21, 2013, 12:32:27 PM by K0OD » Logged
K4EJQ
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Posts: 100




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« Reply #68 on: March 21, 2013, 01:37:47 PM »

AC2EU et al; 630 meters is one of those bands where propagation varies widely from season to season as well as night and day. If your rx is capable to receiver the adjoining NDB bands you should hear your "local" airport's non-directional beacons which, for the most part, run 25 watts or so. Coastal areas may have higher powered marine/aircraft long range NDBs in operation. These NDBs generally operate in the 200-520 Kc band-24/7 with CW IDs. Lists for the NDB, location , power etc. can be found on the internet.

One of the most limiting factors , as far as I am concerned , is the increased amount of thunderstorm QRN from late spring through early fall. Many winter evenings the band is quiet unless of course you are plagued with a high power line QRN. On those nights-WOW, there's DX afoot!!! Propagation is similar to that on the AM broadcast band and 160 meters.

RX range in the daytime usually less than 150 miles-night time , better than 750-1000 miles. I have received NDB's better than 2000 miles on "good " evenings and my antenna is nothing "super". As for experimental stations on the band, many are quite strong when they're on. The most consistant 630 meter signal is that from WD2XSH/7 Beacon. They're are others that are even louder but just not as active. I only look for the CW  and SSB guys as I am not interested in digital modes ( at this time).

Come join us and thanks for asking.

73, Bunky, K4EJQ
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AC2EU
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« Reply #69 on: March 21, 2013, 06:29:50 PM »

OK I tried again later at 1:10 UTC
I heard WD2SXH/32 on 477.90 but very faintly (no s-units)
He's K9WRU in WI. I'm 60 miles from NYC.  Not too bad...

How many watts are they running?
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K0OD
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« Reply #70 on: March 22, 2013, 12:31:10 AM »

You sure it was WD2SXH/32? Some sources list that station as currently inactive. I was hearing WD2SXH/31 in Virginia pretty well this evening.
http://www.500kc.com/600%20Meter%20Stations.jpg


Conditions weren't great tho. The European AM broadcasters around 162-200 KHz weren't copyable here at all, which is rare. Some run over a million watts!

This site has tons of 600 meter info. (but much is old and disorganized)
http://www.500kc.com/
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AC2EU
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« Reply #71 on: March 23, 2013, 08:31:29 PM »

You sure it was WD2SXH/32? Some sources list that station as currently inactive. I was hearing WD2SXH/31 in Virginia pretty well this evening.
http://www.500kc.com/600%20Meter%20Stations.jpg


Conditions weren't great tho. The European AM broadcasters around 162-200 KHz weren't copyable here at all, which is rare. Some run over a million watts!

This site has tons of 600 meter info. (but much is old and disorganized)
http://www.500kc.com/

Well, i AM a CW newbie, but I listened to the call several times and the numbers were indeed:
dit dit dit dah dah     dit dit dah dah dah

I agree that the info was very disorganized, but i found the listing and location and another document that seemed to imply that they are running 20 watts?
I was inclined to believe that 20watts could reach NY from WI if the band wasn't noisy. There were no S units, but it was very readable. Had there been noise, I wouldn't have heard it.
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K0OD
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« Reply #72 on: March 23, 2013, 11:01:42 PM »

Quote
"How many watts are they running?"

I dodged that question because the answer is complicated. Don't know about that particular station but power on 630 meters is usually quoted in EIRP... Effective Isotropic Radiated Power which takes into account the efficiency of the antenna system used. On 630 meters antennas are always very inefficient. It takes a lot of power and a large (by our conventional standards) antenna to produce just 20 Watts EIRP. That's actually a lot of power on 630 meters and probably about the legal maximum when we get a regular allocation there soon.  

Quote
There were no S units, but it was very readable. Had there been noise, I wouldn't have heard it.

There's ALWAYS at least one S-unit if you can detect a signal. S-1 is defined as a "Faint signal, barely perceptible." Note that the RST reporting system dates to 1934. S-meters weren't in common use until much later.

There is ALWAYS noise on 475 KHz!
  
« Last Edit: March 23, 2013, 11:04:52 PM by K0OD » Logged
AC2EU
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« Reply #73 on: March 24, 2013, 06:21:04 AM »


There's ALWAYS at least one S-unit if you can detect a signal. S-1 is defined as a "Faint signal, barely perceptible." Note that the RST reporting system dates to 1934. S-meters weren't in common use until much later.

There is ALWAYS noise on 475 KHz!
  

If I were to give it an RST report it I suppose it would be a 319
I am lucky to be in a semi-rural area where I am away from much of the RF pollution found in more congested areas.
If I have noise, it's usually QRN rather than QRM.
The band was noisy last night, but wasn't on the day that I heard the beacon.
BTW, I believe it was the same station last night, but I can't say for sure due to the  s2 noise floor.

Can you hear it in MO?



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K0OD
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Posts: 2557




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« Reply #74 on: March 24, 2013, 07:13:53 AM »

Minimum number for each of R S & T should be one. Heard a ham give a 5 by zero report to a DX station last week. The DX was so confused that he asked for a repeat:
See http://www.handiham.net/node/156 

The RST system is poor; other systems have been proposed over the decades. Most S-meters have severe shortcomings too. Only Flex receivers have calibrated meters. No receiver has an R-meter or T-meter. Smiley  And even a calibrated S-meter wouldn't be useful where the antenna is a small receiving loop or a Beverage or K9AY type etc. 

Your noise on 630 meters is low only because your antenna is poor. A proper dipole for such a low frequency would be nearly 1000 feet long and hundreds of feet high. My antenna is a 43' HF vertical. A proper 1/4 wave vertical would be 500' feet tall! Tiny antennas can hear well on 630 meters; while they don't pick up much signal, they don't pick up much noise either. 

No, I didn't hear that station last night. My antennas were disconnected amid a rain and heavy snow forecast for St. Louis.
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