[600MRG] Getting Startedv on 600 Meters

[pehamel]

Dick,
First,
Hamming will be different from experimenting, please don't give up.
Then:
The FCC is years behind on granting 137KC to hams in the US, even though it 
was legal worldwide two WARC conferences ago.
We hope they will act on a 630 meter ham band sooner, but the wisdom has 
been to let the FCC finish their (finally issued) proposal to open 137KC to 
hams before pushing for 630 meters.
Thus there are several books and sites on hold to follow the "lead us not 
into temptation" idea and not get hams building something they "must test" 
before it is legal to do so.

About the AT-1. Collectors pay BIG $$$ for them.
It won't do digital. Most new hams don't have the patience to listen to slow 
CW through static and extremely sharp howling filters (even with DSP), but 
they will do slow digital, because they can go get coffee and check the 
computer screen every half hour.
If you drift half a CPS in a hour you will go out of the receiving passband. 
Will your 746PRO VFO hold that tolerance overnight?

A .001microfarad cap is NOT a bypass at this frequency. The AT-1 plate RF 
choke will not choke at this frequency.

The second harmonic of 475KC is 950KC, if you don't have an AM broadcast 
station on that frequency locally, the skip will find one for you.
The third harmonic is 1425KC where there are other AM stations playing soft 
all-night music for old people like me.

For the cost of one crystal you can buy one of several DDS VFO kits that 
will cover the frequency and not drift.
Crystals for this range require great care. I remember an email where an 
experimenter tried to rebuild something like the DX-20 oscillator.
It shattered his custom-cut ($$$$) crystal. (The computer crashed and I have 
lost the email.)

If you live near a population center there may be enough people that you can 
talk into getting on the band to have a CW roundtable. Remember, extreme DX 
with the starting power allowed (five watts EIRP internationally - we don't 
know what the FCC will allow) requires either very slow CW or digital 
signals. After a few years, we expect power limits to be increased.
It may take you a hundred watts from the transmitter to generate five watts 
EIRP. (I hope you know how to calculate or measure EIRP for your loop 
antenna).
www.500kc.com and www.w5jgv.com are good starting points and look at 
http://www.youtube.com/watch?v=rmdqvQk5aV8
.
Again, Hamming will be different from experimenting, please don't give up.
73,
Pat W5THT & WD2XSH/6
w5tht at arrl.net
Unhappy tubes blush, unhappy power FETs scatter plastic loudly

----- Original Message ----- 
From: <dickbolt at comcast.net>
To: <600mrg at w7ekb.com>
Sent: Tuesday, May 07, 2013 12:26 PM
Subject: [600MRG] Getting Startedv on 600 Meters


>
> Hi, I have madeseveral runs at GOOLE trying to find articles on building 
> or converting a unit to get on the 600 meter band......No Raly find?
> I still have my old Heath AT-1 & looks pretty good. I have another one 
> that is a bit sick! On the assumption any start up unit will be crystal 
> controlled, converting an old rig like an AT-1 might be a way. I have an 
> acre to make a circular  loop antenna long & have now a full sized 80 
> meter 1/2 wave dipole up. My 746PRO seems to tune that band, but do not 
> know when to listen? Obviously a new final coil will be needed in AT-1 
> tank ckt! Possibly a tank ckt larger variable cap.
> Where do I find more advice on getting on band & buying crystals. I think 
> I have a 500 KC xtal there might be a way to move it like the old days? Is 
> there a 160 or 80 Mtr net that meets to talk this?
> Dick in Far Western MD W1DGA.
> _______________________________________________
> 600MRG mailing list
> 600MRG at w7ekb.com
> http://w7ekb.com/mailman/listinfo/600mrg_w7ekb.com