Tommy, if I may ask:
What did ICM charge you for that
580 kHz crystal?
Also, was it really a 580 kHz crystal,
or was it some other frequency that you
needed, such as a crystal frequency that is divided
down to the operating frequency.
I am sorry that you feel frustration in trying
to get your station working. I know that you
are looking for a good stable coverage area,
and I can't blame you there.
I'm sure you know this, Part 15 radio can
be pretty frustrating - but the challenge of
getting the set-up to work can be rewarding,
once you have gotten there. Still, I understand
how you feel. To tell the truth, I am quite
impressed with what you have accomplished so far.
My station is experimental. A couple years ago,
it did broadcast around the town with some pretty
good success. People were able to listen in their
houses (on good radios) about 800 to 1000 feet away.
Considering the electrical noise here, I thought that
was pretty good. In the car, the station went two miles
in some directions. I remember hearing the station
on the car radio two miles away. There was some noise,
but it was completely listenable. If you have not
read any of my posts, the set-up operated under Part
15.219 with an SS-Tran AMT-3000, a slightly less than
3 meter stick ground mounted, and 16 ground radials.
It took me a couple of years to get it right, but I
was not in a hurry. I do have to say, that there were
some times I was very frustrated and disappointed
when things didn't work out. But eventually it turned
around. Changes of weather changed the coverage pattern
and that problem was never solved.
Anyway, good luck. I'm sure RFB can help you. Amd then all of us will learn more about it.
Best Wishes,
Bruce, DOGRADIO STUDIO 2
is 6X the operating frequency, so for 580Khz I ordered a 3.480mhz rock. It is "Commercial Standard" tolerance, -25ppm @ 26C, +/-30ppm from -10+60C, HC-6/U or HC-48 Style 10Khz spacing. LPB manual says 32pf shunt fundamental but the ICM crystal is series shunt catalog #705047 cost about $30 + shipping.
Surplus Sales has a bunch of crystals at a low price, check there before ICM.
http://www.surplussales.com/Crystals/Crystals.html
International Crystal MFG
10 N Lee Ave
Oklahoma City, OK 73102
Attn: Sara Gore
800-725-1426 x237
[email protected]
I know Part-15 can be frustrating, I did it years ago. Thanks for the words of encouragement, I'm not done yet. 🙂
Tommy J.
AM-580 The Bull!
If it is of any comfort..it took me 4 years to replace all of my CC equipment I once had back in the late 70's and early 80's. Then it took another 2 months combined of research into the power grid system configuration and a lot of trial and error to get the system working like it should be.
The biggest thing to overcome was the ground conductivity and getting the biggest footprint of isolated earth ground contact to complete the RF loop. This was not an easy task as getting the best earth ground footprint for two separate sections of the MW band is a challenge.
Sometimes it comes together quickly, and other times it does not. But then again if everything was that easy, all of the problems facing the world would be solved at the snap of a finger.
Never think of a failure as getting no where or not discovering something new. When it does not work, you found a new way that does not work and requires a new approach..so is a constant learning experience.
Think of it that way and you gain more than you loose.
RFB
Thank you, Tommy, for the
crystal info.
RFB, I just thought of something.
Have you ever encountered a CC set-up
where RF was getting back into the
studio equipment?
Bruce, DOGRADIO STUDIO 2
"Have you ever encountered a CC set-up
where RF was getting back into the
studio equipment?"
Only in situations where the RF power level is set too high, or when the coupler has insufficient isolated Earth ground path or improper match to the TX either due to a faulty coax between the TX and coupler, or a defective or burnt up input toroid transformer inside the coupler.
In rare cases with a properly installed system causing RF return into studio gear, the remedy is to do one of two things:
1. Use cheap Radio Shack snap-on RF chokes on all power and audio wiring in the studio.
2. Increase the Earth ground return path footprint using more ground rods or buried ground wire. The Earth ground lead should be as short as possible between the Earth ground and the couplers neutral connection point.
In a CC system loading up to the neutral line, that Earth ground path is just as critical as the ground radial system is to a 3 meter stick. And without that excellent ground radial system, or excellent isolated Earth ground path, both the 3 meter stick and CC neutral loading does not work too well.
RFB
As I anticipate the return of my LPB
RC-6A, I've been thinking about ways to
get it to function correctly. That's why
I thought of that question.
Best Wishes,
Bruce, DOGRADIO STUDIO 2
Anytime. I should point out something about the RC-6A crystal. That unit must use a crystal that is "on frequency"..meaning the crystal has to be the operating frequency you wish to transmit.
So if you want to transmit on 600Khz, the crystal must be a 600Khz crystal. The RC-6A does not use any multiplier or divider in the oscillator. Only the solid state models require a crystal 6 times the operating frequency which is then divided down to the operating frequency.
I cant remember if your unit has the tuning meter, or the neon bulb on the output tank. There were different versions of the RC-6A where some had a meter, others had the neon bulb.
When tuning up if it has the meter, tune as usual (dip). When tuning up if it has the neon bulb on the output tank, tune for a peak in brightness of the neon bulb.
Hope you get that unit soon and up and running!
RFB
Hi RFB!
Thanks for the words. I am really looking forward
to the return of the RC-6A. As mentioned, my good
friend didn't have time to work on it.
We do know that the unit needs crystals that are fundamental
ones for the operating frequency. I do have a crystal for 860 kHz,
(it actually says 860 kC on it) but it is a very bad channel.
There is a station on 840 3 miles away, and on 880 is WCBS in
New York, which is a very good all news station. Even though they
are 100 miles away - we listen to them quite a bit because there is
no all news station locally. 860 is absolutely swamped at night by
a Canadian broadcaster. Even though they are French language, I
do stop on that channel at night sometimes and listen. Sometimes
they play some interesting music.
I had a crystal for 640. There was a time, as you know, when 640
was pretty much clear everywhere in the U.S. Unless you lived near
KFI in L.A., or near the few daytimers that were on 640 then, such
as WHLO in Akron, Ohio.
By the time I got the transmitter, 640's clear channel status was
coming to an end. So that rock became useless pretty quick.
I had some oddball crystals for 921 and 944 kHz which worked
in the transmitter, but were useless because of the they were split
channels with other strong stations nearby.
My friend and I were thinking of ways to make the transmitter
better. There is no doubt it needs new 6AL11s. You can switch
the tubes around and the performance of the transmitter will vary.
But if the correct tubes are in the correct sockets, you will get
6 watts out with about 70 percent modulation. I hope getting
new tubes solves that problem and that the modulation will go
back to 100 percent. As far as I can tell, there is no hum on the
carrier. I think the power supply caps are OK. Maybe they were
replaced somewhere along the line. I am not capable of recapping
the unit myself so I hope that is still the same.
My friend was going to build a crystal oscillator that used a rock
that was 2 or 4 times the operating frequency. This would be
divided down to the desired operating frequency. Then he was going
to put some kind of small RF amp on it so it could drive the transmitter.
He was going to modify the existing crystal oscillator in the transmitter
so this would be possible. So, say - for instance - you wanted to go
on 530 kHz. You could use a 1060 rock, or 2120 kHz - that sort of
thing. He is more than capable of doing this. But he just doesn't
appear to have the time. He is a great friend, and I know he would
do it if he could. Of course, this scheme would have been good, because
crystals that are over 1 MHz are less expensive than those that are below.
I have reason to believe that this particular RC-6A may only cover the low
end of the AM BCB. I say this because the two tuning adjustment coils (?)
on the inside seem to be near the end of their range. One of them is
really badly chewed up. To adjust this coil, you can't use a screwdriver.
You have to use a pair of needle nose pliers very carefully.
So, I guess I already said this - but I plan to go with 1020 kHz, daytime
only. 1020 is empty during the day. WPHT in Philadelphia, PA pounds
in after dark. 1020 is as close to the low end of the AM band as I
can get for not much money. One of our friends here on the board
gave a cool link for inexpensive crystals that are below 1 MHz. However,
they are all for frequencies that are splits. 535 kHz is available, and
that is very tempting. It would work on all of the analog antique radios
in the house. You would not be able to try to track the coverage on a car radio,
however.
I would love an elaborate carrier current system that covered a wide
area, but there isn't two much I can do about that now. I will be
satisfied just to have the RC-6A running. This unit doesn't not have
a tuning meter. But the neon light on the inside works fine.
All of my projects here are mainly on hold. The 13 MHz rig, the Gates board,
the solar repeater, and the new AM Part 15.219 outside set-up. I just
have too much going on. Every couple of weeks I'll do a little bit with
something, but things are real slow.
Anyway, thanks for your information. I like talking about the RC-6A. It
must mean a lot to me, because, even though I have not been able to press
it into service, I have kept it all of this time. 25 - 30 years, something like that.
Best Wishes,
Bruce, DOGRADIO STUDIO 2
Bruce MICRO Dog 2, when you get the RC-6A back on the AM band, I will hire a brass band to come down for a sign-on ceremony, if you cover the air fare both ways, hotel accommodations, bar bill and music royalties.
Just like you I dream of being on the power wires with my radio station.
Not being on the air is only slightly less than being on with micro power, so for the Part 15 man dreams are as good as doing.
Hey fella, are you day dreaming?
Yes. I have ground radials under the whole neighborhood and my skywave opened up at this blond's house in the suburbs and she's invited me to a dinner weekend with her Sony AM FM radio.
I wish I could afford to bring you over here.
I'm in agreement with everything else that you said.
Isn't "blond" also spelled with the letter E on the end
as in: "Blonde" (?)
That's all I can say about that subject.
Although I think that all of us guys think that we think
the same.
And we probably do.
Think.
About that.
Yup.
Bruce, DOGRADIO STUDIO 2
Carl, I just read your post again.
So.
Really, you're spending the weekend
with the Sony radio.
And the dinner...
What does the radio eat?
Batteries?
This line of thinking is showing that I'm too
far gone.
I'm not even going to give the usual end to this
post. In other words
bdrs2
It would be quite easy to adapt a PLL to the oscillator circuit of the transmitter. Creating the crystal equivalent tuned circuit is also pretty easy to do.
If after the return of your unit you find that you need more help getting it up and running feel free to shoot me an email and contact number and we can go through the unit step by step and get that puppy barking up a storm on AM! 🙂
RFB
Thank you RFB for your great generosity in offering to give Bruce MICRO Dog 2 a hand with the LPB transmitter. That is so great.
It IS great!!
That is so very kind of you RFB!
When it comes back (I'm not sure when)
I will contact you, even if just to say
Hi and talk about what it's doing. Then I
guess we can figure out where to go from
there!
Thank you again
Bruce, DOGRADIO STUDIO 2
Since deciding to place my planned carrier current station on 970kHz I spend time checking the spot to make sure no one else moves in.
Of course daytime at 970 is always clear, and nighttime is usually clear, but tonight about 10:30 Dennis Miller was on there talking.
I got right on Radio-locator.com and one by one went through every station within several states until I found the one: WGTK in Louisville, Kentucky with 5kW.
Glad to report the DX faded right away and Dennis Miller went away.
There are a ton of stations on 970, with nightime powers as high as 10kW and low as 41-Watts. Some states have more than one 970 station.
Just don't crowd me now.