[CQ-Contest] TS-870 (S)

Vladimir A. Gordienko gord at kron.donetsk.ua
Tue Sep 10 18:28:21 EDT 2002

Hello Don,Bill, et al,
I like this radio very much. I made all proper mods : Intermodulation mod,
filters mod - two of 2.4 kc instead of two of 3kc, RX Ant mod, AGC (eproms)
mod, CW-monitor mod, NB range mod. Most of them are at
http://www.mods.dk . I always take care about correct input levels,
I mean, any strong signal should be no more than about 59+20db
and medium signals are about 57-58. I always use AIP ON for all bands and
additionally switch on the attenuator from 14mc and lower. You should never
switch ON menu #11 "S-meter correction for AIP". Also please take into
consideration that in CW and FSK mode analog filters of 2nd and 3rd IFs
shifted so their passbands overlap only by the desired amont - 500hz for
400hz-setting and so on depending on the setting [QST, february 1996,p.75].
I think it is great contest radio , but only for advanced users.

73, Vladimir ("Bob")  UT1IA  =  EO1I

----- Original Message -----
From: Don Hill AA5AU <aa5au at bellsouth.net>
To: Bill Fisher, W4AN <w4an at contesting.com>; <cq-contest at contesting.com>
Sent: Tuesday, September 10, 2002 12:23 AM
Subject: Re: [CQ-Contest] TS-870 (S)

> Nice info Bill.  Thanks for sharing it.  I just received my 3rd TS-870S
> today.  Although I don't do much CW contesting with it, it takes the cake
> (and a few plaques as well) on RTTY.
> I just wanted to let everyone know that the TS-870S is a little hard to find
> new.  I called around a few of my regular places and no one stocked them.
> I did find that they stocked them at AES in Orlando.  Ordered it last Thursday
> and received it today.  HRO told me it was not a special order item.
> I do occasionally get the overload you were talking about, but only on 20M
> when the band is fully of strong signals.  I take care of that by using AIP
> quiets the receiver nicely and allows me to still copy weak RTTY signals in
> between strong ones.
> I bought the 3rd one for two reasons.  I just had to send one in for repair
> a problem similar to what you said except there was total distortion of signal
> both TX and RX.  This was intermittent.  As long as I used the radio in a
> and transmitted on it, it ran fine.  If I took a rest period and did not turn
> radio off, when I came back, everything was distorted.  If I turned the radio
> off for about 30 mins and turned it back on, it worked fine again.  Finally,
> broke like that for good.  I sent it to AVVID two weeks ago and do not think
> I'll have it back in time for CQ/RJ RTTY, so I bought another one.  The guy
> at AVVID told me he things it's a problem with the PLL circuit.  A guy at one
> of regular places on the East Coast who I called first to purchase another
> said he thinks the same thing.  So don't know if the radios have an inherent
> problem or not, but it's the first time I've had trouble with one of mine.
> The other reason of course if to have a spare for my SO2R station (and maybe
> try SO3R RTTY again - last time was too hard to do and not as efficient as
> Although I have no intention of modifying my radios, I wonder if the mod you
> describe will still allow the radio to be used in the FSK position?  I don't
> why not.
> 73, Don AA5AU
> ----- Original Message -----
> From: "Bill Fisher, W4AN" <w4an at contesting.com>
> To: <cq-contest at contesting.com>
> Sent: Monday, September 09, 2002 3:41 PM
> Subject: [CQ-Contest] TS-870 (S)
> >
> > I got rid of one of my FT-1000MPs prior to going to Finland and I sold the
> > other one while I was there.  It is a FB radio, but I got tired of hearing
> > about key clicks and something about the receiver that I can't explain.
> > Yes, I know there is a mod for the key clicks.  I've also been tortured
> > with an RIT problem that makes the RIT jump all over the place when tuned.
> > I had both radios fixed, and the problem came back.  Very frustrating.
> >
> > Anyway, I have been using an TS870 for my remote control station and in
> > WPX we used it on one of the stations.  Kenwood radios just have the best
> > fidelity for whatever reason.  The radio was also easy to use and isn't
> > laced with a bunch of do-dads that I don't need or use.  That is when I
> > got it in my head to give it a try and get rid of the 1000MPs.
> >
> > My first contest with the radios was the NAQP.  Unfortunately, the
> > receiver didn't pass the test.  Under loud signal conditions, the receiver
> > couldn't handle it.  I have the TS-870 and not the TS-870S.  In the S
> > model, they fixed some things with the frontend related to overload like I
> > experienced.  There is also a documented fix for this problem for the
> > TS-870.
> >
> > Between NAQP and the Sprint I decided I would get the modification done
> > and while researching some other stuff about the radio I ran across some
> > documents and emails about installing a 1K mechanical filter in the front
> > end, replacing the existing filter (very wide).  I talked to George and
> > International Radio about this idea, and he told me about a German ham who
> > had recently published an article in the German CQ magazine about
> > installing an Inrad 600 hz (I believe) filter and switching it out on SSB.
> > I don't care for SSB, so switching out the filter didn't matter to me.  I
> > went ahead and ordered 2 400Hz filters from George and installed them in
> > the radio at the same time I did the modification.
> >
> > This past weekend was the CW Sprint.  A contest with some VERY large
> > signals and a great test for receiver crunch.  The results were great.
> > The radio didn't crunch at all and the DSP filtering in addition to the
> > mechanical filter gave me the option to narrow up the passband when
> > needed.  I also like the IF shift on this radio better than the MP for
> > some reason.  I finished with the most QSOs I've ever made in the Sprint,
> > so I think the radios weren't a problem.
> >
> > One of the 870s (K1TTTs) had a pre-existing problem that I discovered
> > right before the contest (thanks N2NT and W8LX).  N2NT was HUGE on 20 and
> > it sounded like he had a chirpy signal and clicks.  I told him so, and
> > W8LX jumped in and said I was the one sounding chirpy.  So I switched
> > radios, and the problem went away.  I'm taking it over to W6XA today to
> > get that fixed up.
> >
> > Bottom line:  I really like the radio.  It is small without knobs designed
> > for children.  It has nice step attenuation, variable CW width, great IF
> > shift ability, smooth RIT, key & keyer input jacks, and receive antenna
> > input (easy mod).  I've had nothing but good signal reports from the
> > critical CW ops on 40M.  I've also heard that this radio is very good for
> > in band phase noise control.  I have not tested it yet, but that was
> > another thing that was bad with my MPs.
> >
> > Negatives: The radio will only work on one sideband now (CW reverse).  It
> > doesn't interface with my auto-switching TopTen band controller.  And,
> > K4BAI has to learn how to use another radio for SS.  I think I'll send him
> > down one to play with before the contest.
> >
> > FYI & 73
> >
> > Bill Fisher, W4AN
> >
> >
> > PS:  George and I tried to get a translation of the German's article but
> > they wanted money to do it, so we passed.  I would contact George at
> > International Radio if you want more information /
> > filters:   http://www.qth.com/inrad

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