hi,

i recently purchased an very nice drake r8 my choice over the icom r75
- i don't regret my decision one bit - a great radio and along with my
palstar one of the best i have owned and i have owned a few. my
question is will an r8a buy me much more in terms of better DX and
audio, sync detection etc. i have heard the build quality is a bit
better on the r8 and also uses the original drake decoder that was used
in the R7. besides these things, will the r8a buy me much more?

thanks in advance, john

No it won't. Short of ergonomics you have the best one IMO.

Frank
K3YAZ

john wrote:
hi,

i recently purchased an very nice drake r8 my choice over the icom r75
- i don't regret my decision one bit - a great radio and along with my
palstar one of the best i have owned and i have owned a few. my
question is will an r8a buy me much more in terms of better DX and
audio, sync detection etc. i have heard the build quality is a bit
better on the r8 and also uses the original drake decoder that was used
in the R7. besides these things, will the r8a buy me much more?

thanks in advance, john

In article . com,
"john" wrote:

hi,

i recently purchased an very nice drake r8 my choice over the icom r75
- i don't regret my decision one bit - a great radio and along with my
palstar one of the best i have owned and i have owned a few. my
question is will an r8a buy me much more in terms of better DX and
audio, sync detection etc. i have heard the build quality is a bit
better on the r8 and also uses the original drake decoder that was used
in the R7. besides these things, will the r8a buy me much more?

The R8B is a much better upgrade than the R8A. The B version has
sideband selectable sync.

Mike

Would some of you receiver experts that lurk here please explain to me
why the selectable SYNC on the R8B is any differient than using the PBT
while in SYNC on the R8A.

Now a receiver that had a limited PBT range ie.. JRC I can see that it
would not give true USB/LSB shift. But on the R8A the PBT will cover
more than the 3khz bandwith on each side band.

Take 5.070 mhz now at 02:18 utc. There is a a pinging sound on the USB
side but not on the LSB. I engage the SYNC in AM mode 6khz filter & I
hear the ping with the PBT set to 12:00 oclock setting. If I slide it
slowly to the Left or the LSB I do not hear the Ping. If I shift the
PBT to the right or the USB & the ping is there.

Is this not the same as selecting USB or LSB on the R8B SYNC ?????

73, Ken

Mike wrote:
In article . com,
"john" wrote:

hi,

i recently purchased an very nice drake r8 my choice over the icom r75
- i don't regret my decision one bit - a great radio and along with my
palstar one of the best i have owned and i have owned a few. my
question is will an r8a buy me much more in terms of better DX and
audio, sync detection etc. i have heard the build quality is a bit
better on the r8 and also uses the original drake decoder that was used
in the R7. besides these things, will the r8a buy me much more?

The R8B is a much better upgrade than the R8A. The B version has
sideband selectable sync.

Mike

Ken Wilson wrote:

Would some of you receiver experts that lurk here please explain to me
why the selectable SYNC on the R8B is any differient than using the PBT
while in SYNC on the R8A.

Now a receiver that had a limited PBT range ie.. JRC I can see that it
would not give true USB/LSB shift. But on the R8A the PBT will cover
more than the 3khz bandwith on each side band.

Take 5.070 mhz now at 02:18 utc. There is a a pinging sound on the USB
side but not on the LSB. I engage the SYNC in AM mode 6khz filter & I
hear the ping with the PBT set to 12:00 oclock setting. If I slide it
slowly to the Left or the LSB I do not hear the Ping. If I shift the
PBT to the right or the USB & the ping is there.

Is this not the same as selecting USB or LSB on the R8B SYNC ?????

73, Ken


With PBT, the ability to attenuate the unwanted sideband is limited by the
skirt selectivity characteristics of the filter.

With selectable sideband sync detectors, the unwanted sideband is cancelled
by the circuitry. This can be significant if the detector is well tuned.

The two are not the same.

craigm ) writes:

With PBT, the ability to attenuate the unwanted sideband is limited by the
skirt selectivity characteristics of the filter.

With selectable sideband sync detectors, the unwanted sideband is cancelled
by the circuitry. This can be significant if the detector is well tuned.

But of course, how much a phasing type circuit attenuates the unwanted
sideband is a reflection of how precise the components are, and how
well balanced the circuit is.

And one reality is that "sync detectors" came into common use in relatively
low end receivers. Before the Sony 2010, I can't think of any receiver
that had a built in sync detector. The advantage in that and other low
end receivers is that it does allow "narrowing" the selectivity without
the cost of a filter. It is cheaper to use some passive components and
an IC than to add a good IF filter.

To make a fair comparison, one actually has to compare the receivers,
rather than compare techniques. Because while passband tuning does
indeed reflect on the skirts of the filters used, phasing-based selectible
sideband depends on the components and circuitry used.

Once you start paying for a receiver out of the portable category, chances
go up that the filters are better than run of the mill ceramic filters,
which means their passband tuning may be fine. (And I actually can't
think of an instance of passband tuning in a cheap receiver.) On
the other hand, there are lots of relatively inexpensive receivers with
not so great ceramic filters that do use the phasing method to get selectible
sideband, and since those are lower cost receivers, one might wonder how
good the phasing networks are.

Fifty years ago, people would buy phasing type SSB adaptors for their
receivers. They wanted an actual product detector, rather than the
"envelope detector" that came in their receiver, because SSB was
coming in and they wanted to adapt. The selectivity of the receivers
were often limited, because they'd been intended for AM reception.
So an ssb adaptor with the phasing method allowed for improved selectivity
with relatively low cast and no need to modify the receiver (other than
adding a point to connect the adaptor). But nobody claimed this
was better than a good IF filter in the receiver.

Michael

Michael Black wrote:
And one reality is that "sync detectors" came into common use in relatively
low end receivers. Before the Sony 2010, I can't think of any receiver
that had a built in sync detector. The advantage in that and other low
end receivers is that it does allow "narrowing" the selectivity without
the cost of a filter. It is cheaper to use some passive components and
an IC than to add a good IF filter.

The "sync" detector of the ICF-2010 was originaly a gimmick. Sony took the old,
tired, IFC-2001 design, clean it up, improved the reception and microprocessor,
added air band, but still needed something to really make the radio different
than the other 2001 derived radios which were coming onto the market.

By the time they were designing it, AM stereo was a commercial failure in
the U.S. Sony had a warehouse full of custom AM decoder chips and no where
to put them. One of their engineers figured out how to convert them to
a sync detector and put it in the 2010.

It was a great success.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

OK Thanks for the Info.

When the unwanted sideband is cancelled by the circuitry how do you get
the 6khz bandwidth instead of 3khz.Or maybe you don't ????

I am talking/asking about the Drake R8A vs R8B receivers only... with
the bandwidth set to 6khz & AM SYNC mode.

Learning all the time.

73, Ken

craigm wrote:




With PBT, the ability to attenuate the unwanted sideband is limited by the
skirt selectivity characteristics of the filter.

With selectable sideband sync detectors, the unwanted sideband is cancelled
by the circuitry. This can be significant if the detector is well tuned.

The two are not the same.

In article . com,
"Ken Wilson" wrote:

With PBT, the ability to attenuate the unwanted sideband is limited by the
skirt selectivity characteristics of the filter.

With selectable sideband sync detectors, the unwanted sideband is cancelled
by the circuitry. This can be significant if the detector is well tuned.

The two are not the same.

OK Thanks for the Info.

When the unwanted sideband is cancelled by the circuitry how do you get
the 6khz bandwidth instead of 3khz.Or maybe you don't ????

I am talking/asking about the Drake R8A vs R8B receivers only... with
the bandwidth set to 6khz & AM SYNC mode.

Learning all the time.

In AM mode, listening to an AM station and with the PBT control at 12
o'clock using the 6KHz filter you have 3 KHz of the lower and 3KHz of
the upper side bands. Rotate the PBT control to 3 o'clock and you have 6
KHz of the upper side band and none of the lower side band. You get the
reverse situation when you turn the PBT to 9 o'clock.

The high modulated frequencies are farther from the carrier so you will
hear an improvement in the audio high end when the PBT control is turned
either way from the 12 o'clock position.

--
Telamon
Ventura, California

In article . com,
"Ken Wilson" wrote:

Mike wrote:
In article . com,
"john" wrote:

hi,

i recently purchased an very nice drake r8 my choice over the icom r75
- i don't regret my decision one bit - a great radio and along with my
palstar one of the best i have owned and i have owned a few. my
question is will an r8a buy me much more in terms of better DX and
audio, sync detection etc. i have heard the build quality is a bit
better on the r8 and also uses the original drake decoder that was used
in the R7. besides these things, will the r8a buy me much more?

The R8B is a much better upgrade than the R8A. The B version has
sideband selectable sync.

Would some of you receiver experts that lurk here please explain to me
why the selectable SYNC on the R8B is any differient than using the PBT
while in SYNC on the R8A.

Now a receiver that had a limited PBT range ie.. JRC I can see that it
would not give true USB/LSB shift. But on the R8A the PBT will cover
more than the 3khz bandwith on each side band.

Take 5.070 mhz now at 02:18 utc. There is a a pinging sound on the USB
side but not on the LSB. I engage the SYNC in AM mode 6khz filter & I
hear the ping with the PBT set to 12:00 oclock setting. If I slide it
slowly to the Left or the LSB I do not hear the Ping. If I shift the
PBT to the right or the USB & the ping is there.

Is this not the same as selecting USB or LSB on the R8B SYNC ?????

PBT is similar in result to using side band selectable sync but the sync
is generally more effective.

--
Telamon
Ventura, California