ID bandsplit of Kenwood TK630 series mobiles

[Bob]

Ok, I'm reviving an old thread.

I'd love to dump my 630 and go for an Orion, but I just can't swing the cash right now.

How do you get a 630 into 6 meters? I know about the software; it just looks like I can't get the VCO to lock properly. Earlier in the thread, it says something about retuning. Anyone care to shed some light?

[KF4SQB]

Bob, I have that information, but it is on another computer that is down right now. I'll try to get it back on line tomorrow night, too late tonight, and I'll maybe send you the information then if someone else hasn't already done so. Off the top of my head, I do remember that it is two trimmer caps in a square metal can in the center of the RF board, toward the front of the radio. On trimmer is for the RX VCO, the other is for the TX VCO. Don't remember which is which right now, but it ain't hard to figure out. Don't remember where the test point to measure is, either, but you basiclly tune for max voltage all the way across the band. Then, tune the pre-selector (four small metal cans, right rear of the RF board, don't remember the numbers, of course!) for maximum signal passage across the band. As I said, I'll try to fill in the blanks tomorrow night if someone else hasn't already done so.

[KenwoodMan]

Okay, I'm another newbie to this site and have the same question on the TK630 lowband 40-50 mHz going down into the 29.00 mHz range. i currently have it programmed and it will only transmit down to 33:60 mHz before the display starts to flash. I would like to know how to retune my radio to also go through the full spectrum of frequencies.

Any help would be appreciated,

Thank You All,

Rick Hill

email:rickhill@pa.net

[KF4SQB]

OK, Bob, here goes. Lay the radio on your work surface with the heatsink facing away from you and the model/serial number label to your left. Remove the cover that is currently facing up, should run pretty much the whole length of the radio. To the rear is a large, square shield. This houses the PA, which you don't need to change. Everything you need to adjust is in the smaller section towards the front of the radio. First, locate Z302, which is a metal box in app. the center of this section. It should have two holes in the top of it. The hole to the right is to adjust the RX VCO, and the hole to the left is to adjust the TX VCO. Just to the right of Z302, you should see two capacitors together, a gap, and a third capacitor. In this gap, you will find TP302, where the VCO voltage is measured. Now, with a volt meter connected to TP302, set the radio to the highest frequency you plan to use. If nessasary, tune the RX VCO adjustment untill you see between 2 and 6 volts dc, or untill it locks (display stops flashing, radio stops beeping), whichever comes first! Then key the radio, into a dummy load, of course, and repeat the same procedure for the TX adjustment. Finally, go to the lowest planned operating frequency and make sure it still works correctly. If not, go back and forth untill you get a happy medium.

To realign the RX preselector, locate L301, L302, L304, and L305. These are located in a row, right to left, in the upper right hand corner of the same section as the VCO. I'm going to assume you know how to align a preselector. You should now be in business! Let me know if you have any problems, and I'll see if I can help you further. I have already retuned two of these units as described, and they both work great!

Tip: As you should already know, don't use a conductive (metallic) tool for any of this, esspecially the VCO adjustment.

KenwoodMan, I would be really surprised if you got that split radio to go that low. You need to find the version with the lower split to do what you want to do.

[Bob]

KF4SQB, thanks for the help. Over the next couple weeks, I'll be moving everything over to my new vehicle, so that would be a good time to play with it.

In all honesty, I've never had to retune a radio, so I really don't know how to adjust the RX Preselector. (The bandsplits on my VHF and UHF MCS2000s are pretty wide) If you could provide that information too, it would be a great help. I'm fairly new in this business and am still learning.

[KF4SQB]

OK, no problem. Inject an RF signal, preferably from a commercial signal generator of some type, into the antenna port. Start at the lowest level possible, and increase the level slowly untill it just breaks the squelch. Adjust the four preselector coils, in numerical order, for peak signal. Continue to reduce the output level of the signal generator as you get the tuning closer to where you want it. You want it to just break the squelch, as mentioned earlier. You should do this at app. the center of the planned frequency range, then verify that it has acceptable specs' at the top and bottom of the intended spread. I managed to keep mine to 0.3 microvolts or lower across the entire 6m band. Also, I forgot in the last post to thank Frank, Radioman1890, who origionally gave this information to me. Good luck, and happy Hamming!

[Bob]

That helps. Looks like I'll have to wait until my R2200A gets here (hopefully) soon. I'll let you know how I make out.

[N1PMA]

Will this same tuning proceedure work on a TK-730HG?? I have one that I need to get the TX VCO just a little lower to cover the entire 2 meter band.

Currently it goes from 146.5 to 174 pretty easily, I do not plan to program anything over 165 so I was thinking of tuning it down to cover 143 to 160ish except to maybe receive the weather channels.

Thank you in advance for any help you provide!!

Craig
N1PMA

[n5tbu]

Yes the same procedure will work for the 730,however,luck will determine how low it will go before unlock.
mod

[N1PMA]

Mod:

Just wanted to update you and the board, to date I have done 6 110watt VHF High band and 6 VHF Low band units with great success. All of the VHF High bands now cover 140 - 165 (used to be 150 - 173) and the Low bands were the odd mid split that I was able to push 3 - 5 Mhz up or down. Both models maintained great sensitivity. Thanks for all of the info and help!!!!

Craig