OK, folks, I am now the proud owner of an Omni VI. I got a year-old demo
model from Ten Tec--had been used at the factory, but had a full year
warrantee). I ordered it with the standard two 2.4 kHz filters, plus
two 500 Hz optional filters. It arrived on the Friday just before the
UPS strike began (whew!). I also ordered a power supply and the Option
1 DSP/firmware upgrade a couple of weeks later--these haven't come yet.
Thanks to everyone on the list who helped me make my decision!
So far, I'm very glad I got the Omni. Like the guy from Wyoming said here
last year, "I'm as happy as a gopher in soft dirt." :-) I've had a
couple of problems and discovered a couple of quirks--nothing that can't
be taken care of.
The major reason why I got the Omni was receive performance, and it
certainly has that. I did side-by-side comparisons of weak signal
receive between the Omni and my Icom 751a. No contest. The Icom is a
good radio, but the noise level on the Omni is lower, and weak signals
are a bit more out of the noise. The audio is much more full-bodied and
pleasant.
I love the Omni's big knobs. I have size 13 or 14 feet and hands to
match :-)
The Omni's PBT is very good, and therefore very critical to tune (my
Icom 751a's was no slouch either).
Note that if you want to use the NAR filter for AFSK, you need the
special #216 500 Hz RTTY filter, which is properly centered for the
standard high tones centered at 2210 Hz. I don't have this problem,
because for RTTY and Pactor, I use "RITTY by K6STI." This program is
DSP based and uses a Sound Blaster PC card as the A/D converter. You
can use any tones you want, and I set mine centered at 700 Hz, matching
both CW filters with the PBT at 12:30. The audio response is better
down there, anyway. For AMTOR and Clover I "survive" with just one CW
filter, and set the PBT to 4:00.
I've had QSOs on CW, SSB, RTTY and Pactor, with good signal quality
reports.
Now, on to the questions and quirks:
- The rig has one problem that will require fixing. On the 10 MHz band,
it tends to go through a drift cycle every ~18 seconds. The rig will
jump down maybe 30 Hz or so (guesstimate), then drift slowly up to the
place where it jumped, them jump again. This happens on both receive
and transmit. I checked all the other bands, and have not noticed it
anywhere else. Bad crystal, perhaps? I'll be calling Ten Tec about
this.
- Signals dropped almost two whole S-units when switching in the 9 mHz
IF's 500 Hz filter (NAR button). Yes, the PBT was properly adjusted. So
I checked the filter gain jumper on the 9 MHz board. It has pins 1-2-3,
with pin 1 closest to the optional filter. It was set properly
according to Figure 1-5 in the manual, which says that pins 1-2 should
be jumpered for 500 and 250 Hz CW filters, and pins 2-3 for 1.8 and 2.4
SSB filters.
But when I moved the jumper to pins 2-3, the loss on switching in the
NAR filter was reduced to only 1/3 of an S-unit. So either the manual
is wrong, or somthing's different about the radio. Has anybody else
observed this?
- The PBT 12:00 center position is correct for LSB and CW. But on USB,
the signal centers at 1:30. Is this normal, or am I out of alignment?
- I ordered the Ommi with a hand mike. The mike didn't work. It turned
out to be a broken yellow wire at the PTT switch, which I quickly fixed
myself. No need to call the factory for that! Gave me a scare, though.
As I rewired it, the Ten-Tec hand mike does not put out audio unless the
PTT switch is pressed. I think this is normal, because I believe I saw
where the wire broke--2 yellow wires connect together at one end of the
PTT switch. Anyway, this is bad for people who want to use VOX. It's
great for people like me who switch from voice to AFSK digital all the
time. I don't want to have to constantly disconnect the mike to avoid
mixing audio with my AFSK, which I feed into the "audio in" jack on the
back panel. When I wire up another good mike I have to the Omni, I'm
going to duplicate this configuration.
- The radio runs warm. Especially on RTTY--even at half power, the
final's heat sink gets downright hot. In fact, the heat sink gets
fairly warm even when using the TUNE position with the rig putting out a
few watts (I did this into a dummy load for a few minutes to check the
transmit signal stability). I've stood a little computer power supply
fan behind the radio blowing on the heat sink. I figure it's like
chicken soup--it couldn't hurt :-)
- The meter is undamped, and when transmitting at full power, it often
hits the stop at the right side. Is this normal?
- I can't figure out how the SWR (reflected) meter is supposed to work.
Is there a "set" point on the "forward" scale where the reflected meter
is then accurate for SWR? I didn't see this documented, only that it
"reads SWR directly". Yet the reading changes as you raise and lower
the power, as I'd expect from a standard single-needle meter.
- When switching from fast AGC to slow, AGC sometimes jumps way high and
hangs for over 5 seconds, effectively muting the receiver. This seems to
happen only the first time I switch, and then it won't happen for a
while. A workaround is to turn down the RF gain or shut off the AGC
before switching. Is this normal?
- Question: Does the ST button (sidetone adjustment) actually move the
BFO, or is it audio DSP?
- Pages 4-10 and 4-11 in my manual are blank. The table of contents
says 4-11 should have the circuit description of the 9 MHz IF board,
which I can't find. Other blank pages are documented as such on the
previous page. I think I'm missing something.
- I run CW at about 18-25 wpm. The internal keyer, in Curtis mode B, does
seem a little reluctant to generate the last element of "Q" or "K"
sometimes when I squeeze rather than move my fingers back and forth. Does
anyone know why this is?
Don't let these few things fool you. I'm one happy camper with this
Omni 6.
73,
Peter (KD7MW)
Peter A. Klein (pklein@seattleu.edu) : -----==3== --- ---
Network Administrator, LAN/WAN/Novell : | | | | | | | |
Seattle University, 296-5569 : @| @| @| @| @| @| @| @|
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