[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Homebrew 70cm uplink?




> I'd like to have a way that 'no-coders' can >do more than mode J-FM

John, this is not EXACTLY what you asked for, but......

Call me crazy - I bought a cheap Radio Shack HTX-10 for IF purposes. These
rigs are discontinued, and were closed out at RS for $49 not long ago. Many
are for sale on Ebay.

The HTX-10 features USB/LSB/FM/AM and with a simple interface circuit, CW.
It is not a IC-756Pro, but will work as an inexpensive IF rig.

I built a simple Hamtronics 10 meter to 2 meter receive converter, and
combined with the HTX-10, I now have a backup receiver for AO-40. This could
also be used for full-time telemetry monitoring, etc.... I've tested this as
the receive side of my AO-40 station -- It does work!

As for other uses for a 10 meter rig,
I came across a plan for a 10 meter to 70cm transverter:

High-Performance, East-to-Build 432-MHz Transverter -- by Ed Krome KA9LNV
August / September 1991  QST magazine

Having a rig that you can't transmit on isn't all bad, either.. It might
just motivate one to upgrade..

Correct me if I'm wrong, but I believe it would be legal for a no-coder to
use AO-7 in mode A. I'm sure a few people have even used a 2 meter FM rig to
uplink in CW by keying the ptt with no audio modulated.

73,

Kyle Yoksh
K0KN
Olathe, Kansas

----- Original Message -----
From: "John Mock" <kd6pag@qsl.net>
To: <amsat-bb@AMSAT.Org>
Sent: Saturday, November 08, 2003 11:23 AM
Subject: [amsat-bb] Homebrew 70cm uplink?


> I'd like to have a way that 'no-coders' can do more than mode J-FM
> without either buying expensive equipment, especially something they
> won't have much use for otherwise.  So a satellite transciever wouldn't
> qualify, nor would a transverter using HF gear.  But a 6m transverter
> might be OK, since 6m SSB is something that they could use for other
> things[*].  Used gear might work if one has an elmer, but without help,
> that sounds like a difficult option for someone who has no idea what
> they're buying.
>
> I know that given an AIDC downconverter (or equivalent), a scanner or an
> HT with all-band receive (such at the Kenwood F6A or F7E) is adequate for
> hearing AO-40 with a covered BBQ dish, and given an Arrow-type antenna,
> also hear AO-7 and the Fuji birds.  But what about the uplink?
>
> I've thought about building a T2 phasing transmitter kit, but there is
> still the problem of going from its QRPp (+10dBm??) output to something
> capable of driving 10-35W PA or module.  And then, what to use for that?
> One would also need a reasonable stable tunable LO to drive the thing.
>
> One could up-convert from 6m, but MJF 6m QRP rig is USB only.  So i've
> thought about using a high level mixer with a ~486 MHz LO followed by
> something like a helical resonator or SAW filter to get LSB, which, if
> it can handle that much power, might drive said PA.  It could cover
> the passband of AO-40, but it may do little else if the LO is 'rock-
> bound'.
>
> It would be neat if the PA could be mast-mounted, eliminating the need
> for expensive coax or always operating portable.  After all, according
> to my simulations, at most times that squint is decent on AO-40, it
> could be worked with TV rotor and a quasi-polar mount, especially if
> one could tweak the maximum elevation seasonally.
>
> Has anyone else looked at this problem, and what are your thoughts on it?
>
>          -- KD6PAG  (Networking Old-Timer, Satellite QRPer)
>
>
> [*] I remember well the first SSB signal i heard in California with a new
> MFJ 6m QRP rig and homebrew stretched quad (not even roof-mounted yet).
> It seemed like familiar grid square, but i couldn't place it immediately.
> Then i got it, it was VE6EGN, who i had worked many times on AO-57!  (And
> that was during the quiet part of the solar cycle...)
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>

----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home