TK-730 tx VCO mod

[etherxrally]

I have searched all over the net about re-tuning the vco on the tk-730's. I am trying to get more power out of my tk-730 at 145-148 mhz to use as a ham rig. I took off the metal cover to see if i could add a trimmer to the tx vco for adjustment. As many of you know there is only a rx adjustment inside even though there is a hole for the tx side. I guess what Im looking for is if anyone else has modded this to have a adjustment for the tx. if so what value trimmer did you use? tI looks like I can un-solder the component that is at the base of the tx coil and add a trimmer in series like the rx vco has but I have no clue what value they are or should be. Any one have any insight? Thanks

 

[cabletech]

The radio is a 50 watt output radio. That is more then enough for just about any thing.

Just how much more power out are you trying to get?

Also, the VCO has nothing to do with the power out.

 

[etherxrally]

when you program the radio down to ham bands which it is not intended to do from the factory you get very little power out. In the 2M band I have it programmed for, it only puts out 5-10W. I was hoping that if i tune the tx vco that it may drive the PA better and give a better power out at lower freq. If I had 25W output I would be happy. I could be off on the logic but I figure its probable not the PA that is causing the low power but rather whats driving it.

 

[cabletech]

Well let me ask, from where did this radio come from, Canada or us? Is it a G model?

For the most part these radios were NOT designed to operate below about 149.000mz stock. (As has been stated)

In order to do ANYTHING with this radio that you wish, you will need a commerical service monitor.

Now, some time back K6LO who used to work with Kenwood, posted on a couple of other formus about this radio not working well in the 2 meter band.

You may try contacting him.

Good Luck

 

[etherxrally]

We have many service monitors including some Motorola 2670 service monitors along with newer IFR service monitors. That will be no issue. The radios I have are tossed out Tk-730's. Not The G model Or High power models. They are good working radios that just wouldn't do narrow band and so they were replaced with Tk-790's. I will search to see if I can find some of K6LO's posts. I don't mind playing around to get these to work better ( if at all) it keeps me out of trouble. So far they work well on 2M with the only down side being not full rated power. I use one to get on a local repeater with no issues. I am just looking to tweak it to work better. I wasn't sure if anyone else has tried to adjust the TX VCO to better drive the PA. I appreciate the input. It seems that many guys just move on to radios better suited for 2m but I need a good project I guess. Thanks again and I will see if i can dig up some or K6LO's info.

 

[KB1WIT]

Gonna resurrect this thread since i just opened one with this exact same problem. I have the TK-730H so I get 50W near 144 and 100W near 148. Is there a trimmer i could insert in its spot for a VCO adjustment?