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Re: [TenTec] OT: Question about TS-590 possible problem

To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] OT: Question about TS-590 possible problem
From: "Bob McGraw - K4TAX" <RMcGraw@Blomand.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sun, 7 Oct 2012 21:08:40 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
My comment regarding bandpass filters and more specifically band reject filters applies to HF much like duplexers on a VHF repeater. A notch at the receiver frequency is inserted on the transmit side and a notch on the transmit frequency is inserted on the receiver side. While this is "do able" on HF it does require the operators to be cognizant of the frequency limitations, due to the filters, of the individual stations when two stations are operating on the same band.

In most applications today, bandpass filters are used on the output of the transceiver, thus on both receive and transmit modes, largely to protect other stations operating at the same time and place when they are on different bands. When one puts two stations on one band, much different requirements are demanded of the type and selectiveness of the filters.

73
Bob, K4TAX




----- Original Message ----- From: "Don Allen" <w9cw@yahoo.com>
To: <tentec@contesting.com>
Sent: Sunday, October 07, 2012 11:45 AM
Subject: Re: [TenTec] OT: Question about TS-590 possible problem


Question... why doesn't Bob, Rick or someone else post a query about all of this on the TS-590 Yahoo group? There are some technically-oriented folks on that group, and I thought that Rick was a member. Frankly, I'd find it hard to believe the TS-590 is a wide-band, or random noise generator. If that was the case, it should have never passed the design team's and factory QC tests, and FCC approval.

73
Don W9CW


On 10/7/2012 10:52 AM, Bob McGraw - K4TAX wrote:
If the noise is broadband then it passes through the bandpass filters. I've found that notch type filters are typically more selective but more difficult to use. Thus is the better approach to use bandpass filters or band reject filters? If one plans to use 2 radios on the same band and each employees a bandpass filter then the filters are not effective for either radio as the filters pass frequencies within that band, both on transmit and receive.

Ideally the effective use of bandpass filters must have the ability of the filter to select a very narrow frequency range. Thus one filter tuned exclusively for the CW portion and another filter tuned exclusively for the SSB portion of the band. As one implements filters of higher selectivity the insertion loss, both ways, usually increases. Usually not a problem on receive as most receivers have more than adequate gain. However a 3 dB loss on transmit is a lot of power and heat to be dissipated via the filter, not to mention only 1/2 of the power getting to the antenna. Bummer! Notch type filters are typically sharper with less insertion loss but require judicious operator involvement.

Choice of radios is very important when one plans to operate two or more radios in close physical proximity and specially on the same band. Then one must consider antenna location and orientation. There are many of the current brands and models that will not perform well in "mixed company" although they may be excellent "solo" radios.


73
Bob, K4TAX




----- Original Message ----- From: "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Sunday, October 07, 2012 3:10 AM
Subject: Re: [TenTec] OT: Question about TS-590 possible problem


Guys, I am thankful for every attempt to help, but..

THIS IS THE 4TH TIME I HAVE WRITTEN THAT ***THEY ARE ALREADY USING BANDPASS
FILTERS (BPF)***.
They are either ICE or Dunestar, I didn't ask them which.
They have not tried stubs yet.

Besides, even without bandpass filters, good radios do not transmit
broadband noise that wipes out all other bands.
I was team contesting long before I purchased two complete sets of dunestar
BPFs (15 years ago).
We could run 2 or 3 radios (especially Ten-Tecs) out of the same room with
antennas in close proximity of each other and the only interference was
harmonic related.

We have a lot of experience in team contesting and understand the
technologies required there.
This is from our own experience, not from reading books.

We are simply asking for experience with the TS-590.
I'm thinking the TS-590 is a random noise generator!
After receiving information I have received (off-reflector) I honestly
believe that.

In the meantime the boys have organized a K2 and TS-850 and will repeat the
test.
Soon we will see if it's the radios.

I'll report what we find out.

Thanks anyway for all contributions on the topic of 590 and noise
generation.

73
Rick, DJ0IP


-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Don Jones
Sent: Sunday, October 07, 2012 4:56 AM
To: 'Discussion of Ten-Tec Equipment'
Subject: Re: [TenTec] OT: Question about TS-590 possible problem


I am thinking that if these guys who are having trouble were to add a set of
BP filters it would go a long ways towards keeping the front ends of the
radios from going into gain compression.
Plus if the transmitters are dirty the filters will attenuate noise on the
other bands.

I was reading the contesting section of the ON4UN low band DX'ing book and see that a pair of 1/4 wave stubs separated by a 1/4 wave of coax makes for
a highly effective bandpas filter. If they have 3 spare 1/4 sections of
RG213 for 20M they could fabricate a very effective bandpass filter.

Bandpass filters are standard fair for SO2R stations - same goes for
Multi-two contest stations. Not sure if these guys have considered
fabricating a tri-plexer based upon the QST article. I have built two of
them and they work great. Sounds like they need a little mentoring regarding contest band plans and asset allocation for successful contesting. One note on band plans, 10M and 20M do not play well together. The second harmonic of 20M will come thru loud and clear on 10M. But then if 10M is open, 15M will be too. So drop 20 and go to 10. Basically the 15M station stays put and the
20M station picks up 10M if it opens.

So where are they going?

73, Don KO7i



On 10/5/2012 12:43 PM, Rick - DJ0IP / NJ0IP wrote:
A couple of my friends are preparing for an expedition for CQWW and
are
testing their config.
They have 2x TS-590 transceivers and a pair of yagi antennas in close
proximity of each other (about 75' apart).

The problem, they are seeing a broadband noise as soon as they key one
of
the transceivers.
Even with just 5w of power it is wiping out the other rig on all bands.

My old grey cells seem to remember we discussed this here on the
Ten-Tec
reflector about 6 months ago or so.
Does anyone remember the details of this or do I have my wires totally
crossed?
Was there a fix or have I dreamt this up?

TNX guys, and sorry to spam the group, but if we can get these guys
fixed,
we'll have a nice multiplier in CQWW.

73
Rick, DJ0IP

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