[VHFcontesting] Cross Country Sentry 10 Info

[Keith Morehouse]

The true worth of this project will be reflected in the filtering.

Any rumors on pricing ?

Jay W9RM

Keith J. Morehouse
via DROID 3
On Aug 7, 2014 8:57 PM, "Les Rayburn" <les at highnoonfilm.com> wrote:

> First of all, I should state that I have no financial interest in the
> Cross Country Sentry 10 SDR, nor any ax to grind against competitors. But I
> have gotten some additional information from it's developer that I think
> will be of interest to VHF operators. Overall, this product sounds like a
> real winner for both weak signal and satellite operators. The ability to
> have output on all VHF bands from 6 Meters thru 1.2 GHz would be perfect
> for rovers, and really simplify station design for the rest of us.
>
> Here are the comments I've received from Chris, G4HYG.
> ===============================================================
>
>
> I'm also a VHF/UHF weak signal enthusiast so I appreciate your kind
> comments.
>
> We are in the final development phase of the transceiver and are planning
> to start a KickStarter project in about a month to put the transceiver into
> production.
>
> To give you an idea of the technology used in the transceiver the RF front
> end device is a PGA-103+ low noise amplifier with a LTC5584 as a mixer. The
> PA stage uses the new BLP10H610 device from NXP. This NXP device is due to
> be released this month so it should be available when we are ready to start
> production.
>
> The transceiver will work at 222 and 902/903 MHz for U.S. customers. Our
> intention is to supply different firmware and filter options depending on
> the customers location. For example the E.U., U.S, and Japan have different
> frequency specifications for imported amateur radio equipment. For in-house
> testing and any potential military customers we do have wideband firmware
> but I wouldn't like to release that firmware for general use for obvious
> reasons.
>
> The approach we have taken with our existing SDR receivers is to try to
> design them so that they can use as many SDR programs as possible. The
> Sentry transceiver is somewhat different in that it doesn't divide the LO
> frequency by 4 to generate the 90 degree phase shift for the IQ LO
> injection. Programs will have to use the direct LO frequency without
> division. So far HDSDR and Quisk are the only programs I know of so far
> that will operate directly with the Sentry transceiver on both transmit and
> receive. SDR Radio and SDR Sharp work OK on receive. I'm in regular contact
> with most of the SDR software authors as I try to help them to add support
> for our products so I'll be in contact with them before launch to ask if
> they can add support for the Sentry transceiver.
>
> Regarding the question about bandwidth the internal sound card has a 48
> kHz sampling rate so the span bandwidth is limited to 48 kHz, The
> transceiver will have a IQ output to drive external sound cards up to 192
> kHz. The transceiver is designed as a near zero IF (typically 100 Hz to
> avoid the AM and FM carrier appearing at DC). This helps prevent hams
> unintentionally transmitting out of band. The transmitter IQ chain is
> filtered with a 8.5 kHz filter to reduce the wideband noise that can be
> transmitted along with the wanted signal. We realize that many users will
> want to drive external high power amplifiers and transverters.
>
> Recently I've been testing one of the the prototype transceivers during
> the weekly Tuesday night 4, 6, 2 and 70cm contests run by the RSGB. My
> local club (Bolton Wireless Club) have around 25 members who take part in
> the contest and as they are line of sight with my station it's a tough test
> of any receiver or transmitter during the contest. The latest tests have
> even included using unmatched antennas such as a HF dipole as a VHF antenna
> to see how the RF filtering worked in extreme mismatch conditions. A lot of
> the development time over the last two years has been dedicated to ensuring
> that the receiver is as good as we can make it and that the transmitter is
> clean with regard to wideband noise. All these on-air tests confirmed what
> had already been proved in the lab tests and proved that the design is good
> and now ready for production.
>
> The original YouTube video and the photographs on the web page show an
> early prototype. The production version will have a different case more
> suited to fitting underneath a laptop PC. We are planning to add a new
> video showing a working prototype in action in a week or two.
>
> Thanks for your kind comments about the plan for a KickStarter project.
> I'll update the web page and the CCW Yahoo group forum with regular
> progress reports.
>
> Regards,
>
> Chris, G4HYG
>
> ==========================================================================
>
>
> --
> --
> 73,
>
> Les Rayburn, N1LF
> 121 Mayfair Park
> Maylene, AL 35114
> EM63nf
>
> 6M VUCC #1712
> AMSAT #38965
> Grid Bandits #222
> Southeastern VHF Society
> Central States VHF Society Life Member
> Six Club #2484
>
> Active on 6 Meters thru 1296, 10GHz & Light
>
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