The inaugural edition of Radcom Plus came out today, and the first article is on building a 2m masthead preamp - the DG8. I don't think it's particularly appropriate for handheld use, but looks interesting in that it uses (cheaper) mains relays - whilst I've only had a brief scan the article looks really well written and detailed. I've been looking for a cheaper masthead option for 2m to build and so far the relays have always been the significant cost. Power to this one is also over the coax, so it suits me well.
Radcom Plus is available online for RSGB members - http://rsgb.org/main/blog/front-page-news/2015/04/30/radcom-plus-vol-1-1/
No - I don't work for the RSGB - just genuinely impressed!
Best,
Dominic G6NQO
On 1 May 2015, at 05:09, John Brier [email protected] wrote:
Thanks, I found that at their website:
http://www.hsmicrowave.com/Amateur%20LNA.html
I'm going to use two radios so that won't be an issue.
Man, so they do require power, or at least this one does.
I'm already starting to get tired of trying to track the satellites with the Arrow II. Adding a preamp with a battery pack and a second radio (I've mostly just been listening to the ISS lately) is going to get even more cumbersome, plus you have to operate two radios while compensating for doppler, right? How do you operate portably with your FT-817s? Do you attach one to each hip?! I'm starting to think about circularly polarized antennas I can just set and forget, but with a low power satellite like SO-50 that might not work so well. Hmm.
On Fri, May 1, 2015 at 12:00 AM, Paul Stoetzer [email protected] wrote: I use a High Sierra Microwave LNAA432 preamp powered by a 11.1v LiPo battery pack (AAs or AAAs work fine too). I can work SO-50 down to the horizon with the Arrow Antenna if I have a clear shot. I lost at about a degree on the pass earlier. It's usually S1-2 below a couple of degrees, S7 above 10 degrees, and my FT-817 shows S+ above 30 degrees or so.
You have to be careful not to transmit into a receive only preamp like this. I use two FT-817s, one for receive and one for transmit, so this is not a problem for me, but if you use a single radio, you would need to be sure that the preamp is between the 70cm antenna connection and the diplexer so you don't fry it.
73,
Paul, N8HM
On Thu, Apr 30, 2015 at 11:49 PM, John Brier [email protected] wrote: Since a lot of people are talking about SO-50 right now, let me ask a question:
I did try to work SO-50 once when all I had ever worked before was SO-35, UO-14 and AO-27 and I was horrified by how hard it was to hear and track.
I found a thread on qrz.com where they said it's very helpful to use a preamp for SO-50 since it's so low power, even with the short runs of coax required for an Arrow II satellite antenna. I know almost nothing about preamps. What's the deal? Do they need power to work (active/passive?). What do you recommend?
John Brier, KG4AKV, Raleigh, NC, FM05 _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb