TS850s & Rx Ant. Summary

MARIA zs1afz@zs1ctc.ctech.ac.za
Mon, 18 Nov 96 13:07:36 -0200


Message-Id: 6566_zs1ctc
From: zs1afz@zs1ctc (MARIA)
To: towertalk@contesting.com

Hi to all the guys who have responded,
   Thanks a LOT for all the advice and instructions you have forwarded
to me - I appreciate your help very much! As you will notice from this
summary there are other people as well experiencing the same problem 
and I trust that this info will help them just as much!

Good Luck and DX!
73/88 Maria
******************************************************************************
From: zs1afz@zs1ctc.ctech.ac.za (MARIA)                                       
Subject: TopBand: TS850s & Receiving Antenna                                  

Hi Guys,

   How can I use a RX antenna with my Kenwood TS850s which dont have 
the required socket) without making mods?
   Someone has posted instructions on this topic some time ago, but 
I've accidentally deleted it.
   Your help MUCH appreciated !
73/88 Maria - zs1afz
******************************************************************************

From: W7lr@aol.com                                                            

Hi Maria   I use the TS850 and didnt want to modify it, and have not modified
it.
What I do is to use a little relay box that I built of normal 12 volt plastic
case relays to switch to an external antenna for receiving.  I have switches
in the box so that I can listen on the tx antenna too.  There are other
circuits in the box to select a different exciter or a different amplifier.  
     Other uses for relays are at the switching box at the base of my
vertical antenna to select networks for different bands.  Regular 20 amp
relays are ok for the 50 ohm side of the networks, but for high power you
need open frame hv relays on the network output side that goes to the
antenna.  Other boxes are used to select the vertical antenna (90 foot
irrigation pipe) or 30 or 40 meter lazy-v arrays.  Still other relays are
used to select one of four directions on those arrays - lots of relays!
     Good luck.  73 Bob W7LR   W7LR@AOL.COM
******************************************************************************
From: Tom Wagner <tomwagner@mindspring.com>                                   

The following was posted last September.  Kudos
to Brian, WA3WJD, the author.

Tom
____________________________________________________

Subj:   Re: Beverage preamp
Date:   95-09-17 23:22:37 EDT
From:   CARL02@MACCVM.CORP.MOT.COM (Brian McGinness)
Sender: owner-cq-contest@tgv.com
Reply-to:       CARL02@MACCVM.CORP.MOT.COM (Brian McGinness)
To:     CQ-CONTEST@tgv.com


Bob -

In spite of what Kenwood says about modifying your rig for a second
antenna input, it is not that big of a deal. I had to do it to
my rig, no combination of relays, switches and dummy loads completely
protected the K2ZJ box from getting blown up. No matter what I did,
relays were to slow and the device eventually got zapped!

Of course Kenwood wants to protect themselves (and your rig) from
being butchered. But with a little care, it is quite doable.

I made a short loop of white telfon cable with a male and female
BNC connector, and looped it out of the back of the rig so just
enough of the coax stuck out so the BNCs could be joined. Then I
found the little header connector on the filter board in the radio
that was on the receiver side of the rig's antenna relay.

I then pulled that connector loose, and spent a little time tracking
down a male and female header connector that matched what Kenwood
uses, and installed those on the ends of the white teflon coaxes
sticking in the back of the radio.

For normal use, just connect the BNC's and the rig is normal.
For beverage use, connect an extra antenna switch common and ant #1
to the BNC connectors, and put ur beverages on the other positions.

Sorry everyone had to read this, but there seemed to be some
general interest in this. And I didn't use the "C" word!

73, Brian WA3WJD
carl02@maccvm.corp.mot.com
******************************************************************************

From: Gary Schwartz <garyk9gs@solaria.sol.net>                                


Here you go Maria.  You will have to modify the 850 though....

PROJECT #1 - RX antenna input for the TS-850S

This is near the top of everyone's list when they are asked "What things
bug you about the TS-850S".  I initially overcame this deficiency by 
modifying my amplifier so I could connect a different receive antenna
to the TR relay.  However, I wanted to change things so there wasn't as 
much RF getting into the RX antenna due to close proximity to the 
amplifier's output.  This became a problem when using the same receive
antenna on a second radio (you know two radio operating was going to work
its way in here somehow).

Ville, OH2MM had provided me with instruction on how he modified his
TS-850S to have a separate RX input and this inspired me to try it.
Here are some simple steps to hopefully inspire others:

It took me an unrushed two hours to do all this.


1. Remove the top panel (you don't need to take off the bottom one.

2. Remove the plate which sits between the fan and the back of the
radio.  This covers the output filter PC board.

3. Unsolder the connections to the SO-239 output connector.

4. Remove the three cables from the PC board next to the SO-239.  This
includes two coax and one 3 conductor harness.

5. Remove the two screws holding in the PC board and remove it.

6. Locate the trace that goes from the relay's normally closed contact.
You can use an ohm-meter to find it - probe from the wire that went to the 
SO-239.  You will find a short trace on the back of the board which runs
to a chip capacitor.  Cut this trace and solder some very small coax
to each side of the cut - connect ground to the nearby ground trace.

Make the cables about 4 inches long.

7. Remove the antenna tuner. There are 2 screws in the back and front (you
will need a magnetic screw-driver) and one on the side.  You will need to
carefully unplug two wire harnesses and one coax connector.

8. Drill two holes for phono jacks on the back of the radio.  Be careful
not to obstruct the screw hole for one of the screws in the back of the 
antenna tuner.  The best place is between the RF output connector and 
the groundpost.  Put them on top of each other and as close to the bump
on the back panel as possible.  I used a vacuum cleaner while drilling to 
make sure no metal chips went anywhere.

9. You will find a small hole under the SO-239 where you can feed
the two coaxs through.  Solder them to the phono jacks and reassemble
everything.  I put back to back diodes on the RX antennas input, but
you may not want to do this.  A better thing would be to add a relay to
disconnect the RX antenna input when transmitting.  I took care of 
that in project #2.

10.  Obviously, you will need a jumper cable to make your receiver 
work again.

PROJECT #2 - The switch box:

Parts list - 4 position rotary switch
             DPDT 12 VDC relay
             1 K Ohm pot (optional)
             12 phono jacks (or you can get by with 9)
             mini box for above and knobs.
             Clamp diode for relay coil if not included in relay

This box does two things: disconnects the receive antenna input when 
transmitting and allows selection of the transmitting antenna or one
of three RX antennas when receiving.  The pot can be used for RF 
attenuation if your rig doesn't have one.

The relay gets controlled by the PTT output from your rig that normally
would go to your amplifier.  Then one set of the contacts is used to 
key your amplifier.  Don't forget to put a diode across the coil of
your relay if there isn't one internally.  Otherwise, you will have 
undesired arcing across the contacts of the relay in your radio.

The other set of contacts disconnect the output of the rotary swtich
when transmitting.  The rotary switch selects either the signal
coming from the transmitting antenna (from the TR relay in your rig)
or one of three receiving antennas.  I use two phono jacks per RX
antenna so I can feed them to other boxes for other radios.  I also
use two jacks for +12 volts so I can jumper power to another box.

You can build up one of these boxes in an hour or two.  You can epoxy
the relay to the mini box.

If you want the pot there to act as an attenuator, I just hook it
up like you would a volume control:  one end is ground, the other end 
goes to the output of the rotary switch and the wiper goes to the 
output.  Use shielded cable as much as possible to avoid stray 
pickup.

Have fun!!

73,
Gary K9GS 
******************************************************************************

From: skip@netline.net (skip staub)                                           

Hello Maria,

>   How can I use a RX antenna with my Kenwood TS850s which dont have 
>the required socket) without making mods?

If you receive any good info that is not posted through the 160 mtr
reflector, I'd certainly appreciate it if you could/would copy any such
messages to me.  I also have a TS-850SAT.

Thanks.

73,
Skip
K4TMA
skip@netline.net
******************************************************************************

From: Ed Tanton N4XY <n4xy@avana.net>                                         
Subject: Re: TS850s & Receiving Antenna                                       

The most non-invasive method for this is to use an external
HF-RF-capable SPDT relay to switch to the regular antenna upon transmit.
You set it up 'failsafe' by having its N/C (power-off) position
connecting the 'regular' antenna to the transceiver. Easiest way to
avoid timing/sequencing problems with this is to connect the key (or
PTT) as the activator for this relay, and use a second set of contacts
to then key / PTT the transceiver. That way the relay is set BEFORE the
TX can put out RF. You can use a toggle switch somewhere to take this
'offline' (a N/O switch in series with the relay coil will do) for full
time main antenna use. Note I said this was the quick-and-dirty method.
I have a design for a somewhat more complicated unit that allows all
sorts of insertions of preamps and the like, as well as worries about
timing and mode and the like. But this will do the job for you just
fine.
-- 
72/73

Ed Tanton N4XY      EMAIL: n4xy@avana.net      TEL: (770)579-3933
Voice/MBX/FAX
189 Pioneer Trail, Marietta, GA  30068-3466

QRP-ARCI#7663 G-QRP#6779 OK-QRP#172 QRP-L#758 AdvRC#140 NORCAL#1779
NCDXF SEDXC  
Life Member:  ARRL  AMSAT  IDRA  INDEXA  QCWA                  URL:
Coming Soon                                               

"Think you can, think you can't: either way you're right!"  Henry Ford
****************************************************************************

From: "L. Booth" <lbooth@comm.net>                                            
Subject: Re: [BitBucket] TS850s & Receiving Antenna                           

Maria,

I'm interested in the subject, owning an 850 myself. I don't have the
info but would appreciate a forward if you get some feedback. I thinhout mods to the 850, some sort of PIN diode switched external
box would work. I have a few PIN diodes but have had no time to
experiment yet. 

Let me know if you find something.

73 Lionel N5LB, Bush Louisiana
******************************************************************************

From: Pete Smith <n4zr@contesting.com>                                        

Doesn't the 850 have a transverter socket (DIN plug)?  If so, you'll find
the receiver antenna there.

73, Pete Smith N4ZR
n4zr@contesting.com 
West (bigawd) Virginia
******************************************************************************

From: "GLENN R. JOHNSON, M.D." <GRJOHNSON@VAX1.BEMIDJI.MSUS.EDU>              

Hi Maria!

I have two TS-850's and I use Beverage receive antennas for the
low bands.  I use the I.C.E. company's Beverage Switch Box.

When it is turned on, the receive antenna is the Beverage and when
it senses transmit power, it switches to the transmit antenna.
When the box is turned off, the transmit antenna is both the
transmit and receive antenna.  I've used them for several years now.
They work great!

If you need I.C.E.'s phone number or address, please let me know.
 They advertise in CQ and some other magazines.  I don't think
they advertise much in QST.

73, Glenn

_________________________________________________________________________
Glenn R. Johnson, M.D.        email:      grjohnson@vax1.bemidji.msus.edu
Home:  218-243-2611           BBS:        WA0PUJ@K0LAL.#NCMN.MN.USA.NA
FAX:   218-243-2918           Cluster:    WA0PUJ@WA0PUJ (PacketCluster)
Work:  218-759-5000
                                            "Orthopedic Surgeons
                                             get all the breaks!"
W0GJ, VO2GJ, VP2EZ, VP5H, ZF2RT
    (ex-WA0PUJ)
Soon to be: FR/WA0PUJ & VK0IR op
Homepage:  http://vax1.bemidji.msus.edu/~grjohnson/homepage.html
_________________________________________________________________________
****************************************************************************

From: Ralph W1ZK <lcpvt@together.net>                                         

 AMECO sells the PT-3 all band preamp that can be modified with AMECO's 
simple instructions and a few parts (1 relay, 1 small switch, 1 RCA 
chassis connector and 1 piece of wire) for use with a separate receive 
antenna (I don't use the preamp part for 160, it just switches out of 
line). The PT-3 goes in your regular antenna line out of the TS-850 and 
it senses RF when you transmit and bypasses itself. When you want to use 
the seperate receive antnna you just flip the small switch to your 
separate receive antenna position. The circuit board and the chassis are 
punched for the modification. AMECO will supply the modification 
instructions after you buy the unit & sell the parts needed (10$).
 Amateur Electronic Supply (AES) in Milwaukee, WI (latest catalog) sells 
the PT-3 for $119.95 US, phone 414-358-0333, 8-3337. Their 
E-Mail address is aesham@execpc.com. AMECO's address is 224 East Second 
Street, Mineola, NY 11501 & their phone is 516-741-5030, fax 
516-7741-5031. Sorry, no E-Mail address for AMECO.
 I am using the PT-3 with a TS-850S and the separate receive modification 
and 3 short beverages. It works very well. Good Luck & 73/88s Ralph W1ZK
*****************************************************************************

From: dj2ya@t-online.de (Ulrich Weiss)                                        

hallo Maria...have solved that problem here with a little home brew box with
a relay that is controlled by the PA switching line...inserted between
exciter and linear the relay toggles the output socket of the exciter between the beverage 
(in standby - relay idle) and input socket of the linear (relay active)...the 
relay can also be activated by a manual switch if you want to listen on your 
transmit antenna...all you need is a small aluminium box, 3 SO 238 sockets, 2 
RCA (Cynch) sockets, a switch, 2 diodes and a SPDT relay...I'm sorry that I'm 
not more advanced in e-mail, I'd like to send you the diagram as well, of 
course, but I don't know how...but perhaps my hints give you an idea what to 
do...you can use this device with ALL tranceivers and is absolutely safe, the 
worst that may ever happen (if you make a mistake a some parts fail) is to
send your exciters output to the extra antenna...greetings to the cape..
vy Uli, DJ2YA
******************************************************************************

From: k6ll@juno.com (David O. Hachadorian)                                    

--------- Begin forwarded message ----------
From: k6ll
To: tree@lady.axian.com
Subject: Re: Little projects
Date: Sat, 10 Aug 1996 18:36:08 PST
Message-ID: <19960810.183612.4951.0.k6ll@juno.com>
References: <199608091859.LAA11230@lady.axian.com>

Hi Tree,

Here's another way, in case you haven't seen it. Have fun in
the sprINT. No antennas here in Colorado, so will have to
pass this time.

Dave, K6LL
k6ll@juno.com


This modification was developed by Brian WA3WJD

             TS-850 Separate Receive Antenna Modification

Make a short loop of white telfon cable with a male and female BNC
connector.

Loop it out of the back of the rig so just enough of the coax sticks
out so the BNCs can be joined with a barrel connector.

Locate the little header connector on the filter board in the TS-850 that
is
on the receiver side of the TS850 antenna relay.  Pull that connector
loose.  

Spend a little time tracking down male and female header connectors
that match what Kenwood uses.  Install those on the ends of the white
teflon coaxes sticking in the back of the radio.

For normal use, just connect the BNCs with a barrel connector and the rig
is normal.  For Beverage use, connect an extra antenna switch common and
ant #1 to the BNC connectors, and put ur Beverages on the other
positions.
--------- End forwarded message ----------
******************************************************************************

From: David McAulay <vk3ew@rint.com.au>                                       

Hello Maria,

If you get replies to this can you also let me know, as I also have a ts850sat

Greetings from Australia


David VK3EW
*****************************************************************************

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