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kr1sis
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Joined: Mon May 14, 2012 9:27 pm

Just joined

Post by kr1sis » Mon May 14, 2012 11:44 pm

Good Day,

My name is Jon Aparo I just joined the BATC. I live in Southern New England (Connecticut, USA). Even though I'm not Local I feel like I could be. The city I live in is New Britain (even more local?).

I would like to get hold of a board layout for a 70 cm ATV transmitter. I told a NARL club member that I had joined the BATC, and I have been volunteered to give a 20-30 minute presentation during our local hamfest. I would love to have a 70 cm unit. I am planning to purchase a 23cm set, but I would really like a home brew one also. I am attempting to build a board layout, but I am pressed for time. The hamfest is in less than 1 month. Any help is appreciated, thank you.
I find the resources that the BATC are fantastic.

Have any of you ever noticed that Americans can't spell?

73,

Jon Aparo
KR1SIS

G4EWJ
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Joined: Wed Feb 17, 2010 10:11 am

Re: Just joined

Post by G4EWJ » Wed May 16, 2012 11:57 am

Hi Jon,

In Europe, our 70cm band is 430-440MHz (or less), so I would think your options for ATV are greater in the US. I believe that there is analogue operation in continental Europe, but I'm not sure about the UK.

Digital is popular on 70cm at low symbol rates, but I've seen some discussions in the US that digital on 70cm is not strictly allowed by the regulations, depending on how you interpret them.

Brian

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g7kpm
Posts: 49
Joined: Sat Feb 23, 2008 9:00 pm

Re: Just joined

Post by g7kpm » Tue Jun 05, 2012 3:57 am

Hi Jon,

Welcome to the BATC!

You can purchase a kit for a 70cm ATV AM TX from Minikits in Australia. I own 2 and they work very well.

The URL is: http://www.minikits.com.au/kits1.html#eme44

Another (possibly cheaper) way is to use an old 70cm transmitter and a modulator to modulate the transmitter's PA.

A circuit was published in CQ-TV 124. The article has been posted here at this URL:
http://homepage.ntlworld.com/gb3ggrepea ... yncmod.htm

Hope this helps...

Best 73s,

Jason G7KPM

kr1sis
Posts: 3
Joined: Mon May 14, 2012 9:27 pm

Re: Just joined

Post by kr1sis » Mon Jun 11, 2012 11:44 am

Thank you both.

To get things moving, I went ahead and purchased a board kit. However, I'll be making the board in the 2nd reply --- CQTV 124 . It looks easy and I hope to have the parts in before the NARL fest. I would like to thank the BATC in my presentation and place a big mention in the final credits. Give credit where it's due, and the BATC has a wealth of information and is a great resource. I hope here in the US, we can get more people involved.

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g7kpm
Posts: 49
Joined: Sat Feb 23, 2008 9:00 pm

Re: Just joined

Post by g7kpm » Mon Jun 11, 2012 2:44 pm

Hi Jon,

You are very welcome. I hope your talk goes well and you get some people interested in ATV!

If you have an internet connection at the site, you could broadcast your talk worldwide via the BATC streaming facility.

Just a note on the video modulator, the modulator output connects to the supply rail of the final PA transistor. You may need to cut the track in order to replace the 12v supply with the modulated 12v supply from the modulator. Another thing to note is that you may need to remove any decoupling capacitors from the isolated part of the supply rail to ground otherwise you may get low definition and smeary video.

Additional information on how to connect to the PA is on page 14 of the BATC Amateur Television Handbook available for download here:

http://www.batc.org.uk/cq-tv/archive/handbooks.html

I would be very interested to know how you get on. Best of luck with your talk.

Best 73s

Jason G7KPM

www.gb3gg.org.uk

kr1sis
Posts: 3
Joined: Mon May 14, 2012 9:27 pm

Re: Just joined

Post by kr1sis » Mon Jun 11, 2012 11:21 pm

I hope you don't mind if I thank you and the BATC at the presentation. I also hope your get some people from Connecticut to join. The BATC seems to have the best information on ATV anywhere.

Thank You again & 73,

Jon Aparo
KR1SIS

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