Yes, but the Orion also had Band-Width used in conjunction with IFS.
When you combine BW with IFS, you get the same functionality as PBT.
Without narrowing the bandwidth, the technology is a help but is often not
as effective.
Tnx for reminding me where I had seen IF Shift.
I was trying to remember which rig(s) I had seen that in.
It's been 30 years since I have owned a Drake Line.
I fully agree; the terminology is a bit vague here. In fact Wayne Burdick,
N6KR, the chief engineer at Elecraft expressed that problem too, and went on
to explain the difference between the two technologies as follows:
*** There are at least two kinds of "shifting" covered by these terms:
- In one case you're just shifting the pitch of the I.F. without
changing the bandwidth. A more accurate term would be "Pitch Shifting."
- In the other case you're shifting *two* I.F.s in opposite directions,
reducing the degree of I.F. filter overlap from 100% to something
lower, so that the ultimate bandwidth (at audio) is reduced. The center
pitch of the passband may or may not change at the same time. Let's
call this "Filter Shifting." ***
Source:
http://elecraft.365791.n2.nabble.com/IF-Shift-vs-Passband-Tuning-td392810.ht
ml
IMO, the first is properly termed IF Shift, and the second is termed
Passband Tuning.
But that is after all, just semantics.
So let's agree (I hope) that regardless of what it is called, the IF
tuning/shifting in a single conversion radio is not as effective as the
tuning/shifting in a dual conversion radio (assuming both are implemented
soundly).
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of shristov
Sent: Wednesday, October 29, 2014 8:51 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] repairs
Rick - DJ0IP / NJ0IP <Rick@DJ0IP.de> wrote:
> Actually Sinisa, what you just describe is called "IF Shift", not
"Passband Tuning".
...
> "IF Shift" moves the entire passband of a single filter, whereas
> "PassbandTuning" moves the relative position of two filters. PBT is
superior.
Well, the terminology isn't standardised well enough.
Orion's PBT works exactly as "IF Shift" in your description, and I'd guess
that Palstar rig does the same, judging from LSB and USB marks around PBT
knob.
Drake R4C had the same thing, and called it Passband Tunning, also had LSB
and USB marks around the knob.
73,
Sinisa
>
>
>
> I still maintain that PBT canNOT be accomplished with a single IF.
>
>
>
> I'm fairly certain of this, but not quite 100% certain, however that's
> the way I remember it from my schooling long ago.
>
>
>
> So if the TR-30A claims PBT and single IF, it is technically wrong.
>
> Then they should re-label that knob "IFS".
>
>
>
> For the record, IFS is a lot better than having nothing at all.
>
> It's just not as good as PBT.
>
>
>
> 73 - Rick, DJ0IP
>
> (Nr. Frankfurt am Main)
>
>
>
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of
> shristovSent: Wednesday, October 29, 2014 7:34 AM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] repairs
>
>
>
> Rick - DJ0IP / NJ0IP < <mailto:Rick@DJ0IP.de> Rick@DJ0IP.de> wrote:
>
>
>
> > Could someone here please explain to me (technically) how PBT
> can work
>
> > with single conversion?
>
>
>
>
>
> PBT (with constant filter bandwidth) is easily done with single
> conversionand single filter.
>
> Just vary VFO and BFO frequencies simultaneosly to keep the resulting
> carrier frequency unchanged.
>
>
>
> 73,
>
>
>
> Sinisa YT1NT
>
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