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eHam Forums => Elmers => Topic started by: DU7DVE on November 28, 2015, 06:03:27 PM



Title: Kenwood TS 430 RF output control mod
Post by: DU7DVE on November 28, 2015, 06:03:27 PM
Greetings fellow hams. Is there a modification for a kenwood ts 430 that allows a controlling power output that's separate from the mic gain? Thanks in advance.


Title: RE: Kenwood TS 430 RF output control mod
Post by: KD8GEH on November 28, 2015, 09:17:50 PM
The RF output knob on the front panel.  Its the outside knob of the mic gain marked "CAR" for carrier. No mod necessary.

73,  Dave


Title: RE: Kenwood TS 430 RF output control mod
Post by: KA5IPF on November 28, 2015, 09:23:50 PM
On the 430 there is not a power control in SSB mode except for turning down the mic gain. The Car control sets CW/AM/FM power but does not affect SSB.


Title: RE: Kenwood TS 430 RF output control mod
Post by: KD8GEH on November 28, 2015, 09:31:23 PM
Never noticed on mine, or its been modded... I stand corrected OM.  Thanks.  Mods.dk shows a SSB power mod , you can join for free.  http://www.mods.dk/index.php?ModelId=520 (http://www.mods.dk/index.php?ModelId=520)

Heres what wa9z recommends

1. Power off, remove top cover.

2. Locate R178(2.2k), near CONNECTOR 22, just left center of the YK-88 CW filter slot.

3. Cut the top lead of R178. Leave enough lead protruding from the resistor so it can be resoldered should you ever want to reverse it.

4. Replace top cover. Dress speaker lead away from slide switch group and any pinch points.

5. CAR control now adjusts all modes RF power output.

6. Modification complete. wa9z 6-2015

73, Dave


Title: RE: Kenwood TS 430 RF output control mod
Post by: DU7DVE on November 28, 2015, 11:58:19 PM
Thanks for the quick replies elmers. Much appreciated.


Title: RE: Kenwood TS 430 RF output control mod
Post by: K8AXW on November 29, 2015, 09:32:13 AM
I am presently building an external "box" to will allow me to vary the SSB output on my Kenwood TS-830S by introducing an ALC voltage.  No opening, cutting, etc. necessary.

Oh, it also has other features.  The thing is simple to build.


Title: RE: Kenwood TS 430 RF output control mod
Post by: DU7DVE on November 29, 2015, 01:55:36 PM
I am presently building an external "box" to will allow me to vary the SSB output on my Kenwood TS-830S by introducing an ALC voltage.  No opening, cutting, etc. necessary.

Oh, it also has other features.  The thing is simple to build.

That sounds really interesting. May I know more about it?


Title: RE: Kenwood TS 430 RF output control mod
Post by: K2DC on November 29, 2015, 04:33:14 PM
It's probably something really complex, like a 9V battery and a pot.

73,

Don,  K2DC


Title: RE: Kenwood TS 430 RF output control mod
Post by: W8JX on November 29, 2015, 04:47:13 PM
It's probably something really complex, like a 9V battery and a pot.

73,

Don,  K2DC

Yep. Use a 35k pot or so and place 9v battery across ends of pot and use wiper to set alc voltage to reduce output. You have to apply a negative ALC control voltage so connect positive to chassis ground.  


Title: RE: Kenwood TS 430 RF output control mod
Post by: K8AXW on November 29, 2015, 07:55:48 PM
It can be as simple as a pot and and 9v battery for sure but this gizmo was pictured here on eHam.com.  I'll research this and direct you to the circuit. 


Title: RE: Kenwood TS 430 RF output control mod
Post by: K8AXW on November 29, 2015, 08:10:08 PM
OK< here's the link to the circuit I am presently working on:

http://www.ad5x.com/images/Articles/XcvrPwrCtrl.pdf

It was designed by Phil Salas, AD5X some time ago and was posted here on eHam recently.  It has more than one function and one or both can be built.  It is indeed a bit more complex than a 9v battery. 

NOTE:  The schematic is kind 'old' style meaning that when wires cross one another with a loop, that's a no-connection.  If the wires cross and there is no loop, they are connected.  This schematic has two (2) of these "connected" cross over points.


Title: RE: Kenwood TS 430 RF output control mod
Post by: DU7DVE on November 29, 2015, 10:16:42 PM
Thanks guys. Much appreciated, this should come in handy. Just when I've already done the diode d49 mod for my TS440.


Title: RE: Kenwood TS 430 RF output control mod
Post by: K8AXW on November 30, 2015, 08:28:28 PM
DVE:  Don't that just piss you off?  Same category as your buddy telling you after buying something, "Gee, if I knew you wanted one of those I could have got you one wholesale!" 


Title: RE: Kenwood TS 430 RF output control mod
Post by: DU7DVE on November 30, 2015, 10:41:34 PM
DVE:  Don't that just piss you off?  Same category as your buddy telling you after buying something, "Gee, if I knew you wanted one of those I could have got you one wholesale!" 

Haha, well that's the way things go.


Title: RE: Kenwood TS 430 RF output control mod
Post by: K6BRN on December 01, 2015, 09:19:48 PM
One option is to simply buy and use the MFJ TPC-150 Rig Output Power Control box.

It has two separate user adjustable pre-settings for tune-up of tube amplifiers or antenna matching networks and regular operation.  It works by providing an adjustable ALC voltage to the rig.  Pretty much the old TS-430/TS-440S "9V battery and a potentiometer" solution refined and put in a  box.  It "works with any rig and amplifier".  60 bucks at HRO.

Note that the TS-430/TS440S "cut the wire" mod for front panel power control has some side effects and is pretty non-linear.  Definitely make sure you leave the PWB and wiring in good enough condition to reconnect if problems pop up.

Brian K6BRN


Title: RE: Kenwood TS 430 RF output control mod
Post by: DU7DVE on December 02, 2015, 04:01:59 PM
One option is to simply buy and use the MFJ TPC-150 Rig Output Power Control box.

It has two separate user adjustable pre-settings for tune-up of tube amplifiers or antenna matching networks and regular operation.  It works by providing an adjustable ALC voltage to the rig.  Pretty much the old TS-430/TS-440S "9V battery and a potentiometer" solution refined and put in a  box.  It "works with any rig and amplifier".  60 bucks at HRO.

Note that the TS-430/TS440S "cut the wire" mod for front panel power control has some side effects and is pretty non-linear.  Definitely make sure you leave the PWB and wiring in good enough condition to reconnect if problems pop up.

Brian K6BRN

What kind of side effects?


Title: RE: Kenwood TS 430 RF output control mod
Post by: K6BRN on December 02, 2015, 09:30:21 PM
The number one complaint is that the power control is very hard to adjust after the mod, because output tends to change in jumps with very small movement of the CAR knob, and part of the knob rotation is "dead" and does nothing.  The number two complaint is that the transmit ALC no longer works consistently, causing overdrive/IMD.

While I do have a TS-440SAT and use it regularly, I've avoided this mod because its clear from the schematic and service manual that this is not a mod the Kenwood engineers ever planned into the radio, unlike many other "cut the diode" options.  Its a pretty crude hack.  So what I'm passing on are comments I've heard and read from people in the TS-440S community who have done the mod, not something I've experienced myself. 

Quite a few have tried out the mod, reversed it and gone the battery and potentiometer voltage injection into the ALC input route, which MFJ has made very simple at the cost of $60 for a neat solution.  But if you have a good junk box and some time, you can build a variable ALC voltage injector yourself, for very little cost.

Hence - go ahead and try the mod out, but make sure it is reversible if you have problems with it.

All the best...

Brian K6BRN


Title: RE: Kenwood TS 430 RF output control mod
Post by: DU7DVE on December 04, 2015, 03:52:32 AM
Thank you. Yes, the control is kind of erratic.