[TenTec] Flex-Radio compared to Pegasus

Tue Jun 7 02:18:36 EDT 2005

----- Original Message ----- 
From: "Duane - N9DG" <n9dg at yahoo.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Wednesday, June 08, 2005 01:31
Subject: Re: [TenTec] Flex-Radio compared to Pegasus


> --- designer <designer at quickdata.com> wrote:
> 
> > I did search the archives but found nothing current about
> > the Pegasus 
> > compared to Flex-Radio SDR-1000. Now that the Pegasus has
> > been 
> > discontinued, is SDR-1000 the only "living" game in town
> > for SDR?
> 
> Actually the Pegasus shares much more in common with the more
> traditional radios out there than the ideal concept of "SDR".
> Yes it has updateable firmware but it is a "tradition radio"
> first and SDR second. Its SDR aspects are confined to its
> inner workings that you as a user have little or no direct
> access to. So in reality other than being 100% computer
> *controlled* it only *minimally* embodies the wide range of
> concepts for SDR. I'm saying this as an owner of several
> Pegasus radios that I *do* like very much. I operate them as
> a collective group under several simultaneous sessions of
> N4PY software that is providing me some key usability
> features that the new crop of $10K+ radios still can't match.
> But I also am realist in terms of what they can ultimately
> do,...or not.
> 
> The SDR-1000 is *much* closer to the ideal implementation of
> the SDR promise. It allows users to work with its inner
> workings of its DSP code if you're so inclined or capable to
> do so. Yes I have one of those too. I like it a lot and find
> it to be a much better RX in terms of filtering, dynamic
> range, and audio fidelity (the Pegasus is only second to it
> for audio fidelity). Its promise is still all in the future
> and has an active and growing user community with a core of
> dedicated programmers shepherding its software to accommodate
> some *very* exciting new ideas for how we will work and
> interact with our radios in the future. These guys are *not*
> just trying to emulate a traditional radio in software, yes
> it will be able to, *and* it will be able to do so much more.
> So the real fun with the SDR-1000 is just begining.
>  
> > As used Pegasus's appear for sale from time to time. Has
> > there been 
> > any comparison between the Pegasus's RX and TX and that of
> > Flex-Radio?
> 
> Here are some of the key comparisons that I can think of at
> the moment:
> 
> 1. IF filter passband shape factor - The SDR-1000 wins this
> contest by far, as you may have noticed the narrower filters
> in the Pegasus are rather broad at their 60 dB points. The
> SDR-1000 will do a 25 Hz, yes 25 Hz filter with very steep
> skirts; it is truly something to behold. The Corsairs, and
> Omni VI I have which have narrow filters in both IF's can't
> match it at all.
> 
> 2. Close in dynamic range - the SDR - 1000 is much better, it
> is amazing how you can slice a weak CW signal out from
> between two stronger signals at +/- 100 Hz away. The Pegs
> shape factor simply doesn't allow it. 
> 
> 3. LO phase noise - SDR-1000 is much better, the Pegasus is
> rather mediocre. 
> 
> 4. Latency of signals through the radio. - The Pegasus has
> essentially no latency, the SDR-1000 currently has
> significant latency, though has improved from what it was. It
> stil might be tough to really get good high speed QSK
> performance out of it because of it. I run 3.2GHz processor
> and the latency is significant. I have not transmitted with
> CW yet so I can't elaborate on keying turn around in detail
> but have been listening to the same signal on two radios at
> one time and can easily observe the latency. 
> 
> 5. Audio fidelity - The SDR-1000 wins handily here. I
> attribute that to the fact that it uses a low distortion
> sound card (or at least you better plan on it) and the fact
> that it is essentially a direct conversion RX. Until the
> SDR-1000 arrived here the Pegasus was the best in this shack
> by a sizable margin as compared to IC-706, IC-765, IC-820H,
> Corsair, Delta, or even a recently acquired Omni VI (no
> option upgrades). 
> 
> 6. Plug it in a go - Not so with the SDR-1000, there is
> plenty to setup and configure. However it is not difficult at
> all if you are comfortable with PC hardware and software
> setup, if not you will do some head scratching. The
> installers for the PowerSDR software are very well thought
> out and work very well. Its defaults are very sensible and
> practical and get you steered into the right direction. They
> also allow for multiple versions to all be installed at the
> same time on the same machine so you can easily go back to
> previous version with re-installing anything. It is fun to go
> back to older versions every now and then just to see how it
> has progressed. 
> 
> 7. Band scope - The Pegasus with N4PY software can
> effectively let you see a large part of the band, but it is
> not real-time. The SDR-1000's panadapter is near real-time
> but is currently confined to just 20kHz; this is largely a
> function of the sound card and the software as currently
> written. The current software only uses 48kHz sampling, this
> limitation is changing in the not too distant future. 
> 
> 8. Open-ended-ness - The Pegasus can do a lot of tricks with
> its RISC-like command structure

Not sure what you mean by that.  Can you givw me an example?
 (look and what both N4PY and
> Callsign Software have done for that radio). It is however
> really rather limited in the grand scheme of things mostly
> due the fact the signal processing itself is contained wholly
> within the radio at all times. It is also constrained by a
> 57K serial connection, The SDR-1000 does not have these
> restrictions at all since the DSP and control work is all
> done in the host PC. 
> 
> 9. The biggest hardware related performance faults I can find
> with the SDR-1000 is that it can be prone to out of band
> signals, for example on 160 I have plenty of AM broadcast
> bleed through. Have not tried really pin down the exact cause
> and in fairness to the SDR-1000 I've been running it in a
> rather exposed lash-up fashion. The other fault that I see
> from time to time is spurs that I assume are from the DDS,
> they are especially pronounced on 6M but are pretty much
> non-existent on the lower bands. 
> 
> Duane
> N9DG
> 
> 
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