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Why isn't there more action on ARRL forum? Sep 13th 2012, 00:48 11 5,715 on 29/1/13
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General Comments Jul 24th 2011, 21:46 22 9,477 on 29/7/11

Latest Posts

Topic Author Posted On
FT8 AG5P 4 days, 8 hours ago
Easy workaround:

Select File > Display or Modify Prefences...
Select ADIF Modes tab
Add... ADIF Mode = FT8
Resulting TQSL mode: DATA

Now, when you run TQSL, ADIF file's FT8 QSOs will be mapped into DATA QSOs for LoTW. ARRL awards category DATA is the same as JT65 and other digital modes. It would be nice to record your Q's as FT8 in LoTW, but it's not necessary.

73 GL Martin AA6E
Electric Field Strength Limit Calculation kj4saf 2 weeks, 4 days ago
Which FCC rules are you referring to?

The basic rule has to do with PEP output power level with no reference to field strength or antenna gain.

If you are referring to the RF exposure (safety) rules, the considerations are different, and rather more complicated. I recommend you consult, if you haven't already done so.

Your calculation seems to be on the right track -- You are looking at the field strength in the far field of an isotropic radiator. But we are rarely in the far field (certainly not for common frequencies at 3 meters separation), and our radiators are never isotropic!

Actual electric field strength depends on many things - distance from radiator, antenna radiation pattern and gain (including transmission lines), polarization, as well as power level and environmental details. It's hard to make an accurate calculation from first principles. Mostly, amateurs are well advised (IMO) to use the broad "safe harbor" rules that say that for a certain frequency, separation distance, and power level you are OK without doing a precise measurement. (And the level is different if you're talking about yourself or your family vs the general public.) If you come close to the "danger" level, then you are supposed to do a real measurement to show that you're OK -- or else reduce power.

73 Martin AA6E
FLDIGI power problem KC8WPW 2 weeks, 4 days ago
You probably want to set your (peak) power level to 100W -- but then turn your mic gain (audio level) down, so that the average power level is 20-30 W. But this depends on what radio you're using. Some radios don't have a mic gain control, and that will be a problem.

If your average power on PSK31 (I assume you're talking about this mode?) is 30 W (or so), your PEAK power will be close to 100W. That's because PSK31 and some other modes transmits multiple simultaneous tones. If your average power is higher than about 30 W, you will be clipping the peaks -- making an unholy mess on the band! (Sadly, this happens all too often.) Your ALC light, if you have one, should never light, and your speech processor (if you have one) should be off. Linearity is your friend!

On the other hand, if you're talking about RTTY or JT65, your peak power is equal to your average power, because these modes only transmit one tone at a time. Linearity is not an issue.

In future, it would help if you tell us what make/model radio you are using.

73/GL Martin AA6E
CW and QRP on 80 meters KE0KCG on 13/7/17
Bob gives the scoop on 80 M, but I'd vote for 40 or 20 M.

For one thing, it's a lot easier to put up a 40 or 20 M half-wave dipole. (66 ft or 33 ft, give or take) You also don't need to put them up so high in the air for the same performance level.

Noise levels and year-round performance are more manageable on 40 and 20, and DX would be easier too. Of course, this assumes you have operating privileges in those bands.

Hope it works out for you!

73 Martin AA6E
What If I Send Non-Standard Size QSL Cards? wv0vw on 5/7/17
Dan - You're right that 4x6 is a standard in the direct mail world. I did a 4x6 QSL at one time. They are accepted by USPS and the QSL bureaus. I think I've seen some European cards in the larger format.

But 3.5 x 5.5 inches is the QSL standard, and cards that size will be easier to mail and to file alongside other people's cards.

I don't have a source for the smaller card stock, though maybe an Internet search would find something. Print shops may use the larger stock and trim it down to the smaller size -- not something you probably want to do. You could contact a friendly QSL printer and ask for their wisdom on the subject.

73 es GL, Martin AA6E

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