VHF X9000 down to Ham Frequencies

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Tim
Posts: 448
Joined: Wed Mar 20, 2002 4:00 pm

VHF X9000 down to Ham Frequencies

Post by Tim »

Picked up a couple of VHF X9000's this past weekend,
and got one of them programmed with both ham freqs
and some public service stuff I use.

The PS works fine, but the 146 & 147 freqs don't transmit,
although the receiver can hear them. Guess the TX VCO isn't
quite right.

I'm sure somebody has converted some.. what do I need to do?

Thanks,

Tim
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n7maq
Posts: 1440
Joined: Tue Nov 27, 2001 4:00 pm
What radios do you own?: Mocom 70 w/scan!!

Re: VHF X9000 down to Ham Frequencies

Post by n7maq »

Tim wrote:Picked up a couple of VHF X9000's this past weekend,
and got one of them programmed with both ham freqs
and some public service stuff I use.

The PS works fine, but the 146 & 147 freqs don't transmit,
although the receiver can hear them. Guess the TX VCO isn't
quite right.

I'm sure somebody has converted some.. what do I need to do?

Thanks,

Tim
Tim,

There is some HAM RSS that will program the VCO as a "range 1.5" and will allow for full 2 meter use with out any VCO mods. You can't buy that RSS from Moto so you will have to find someone who has it and have them program your radio. I have programmed several units this way and it works great. You will still need to tune the front end, and that is best done by sweep tuning it if you can.

If the X9000 would just do N/B and P25.... They were/are great radios.


Jim
Tim
Posts: 448
Joined: Wed Mar 20, 2002 4:00 pm

Re: VHF X9000 down to Ham Frequencies

Post by Tim »

Hi Jim,

I've used a version of the RSS that allows programming from 136 - 181.
(that's one of the selections when you create the plug).
The others are:

136-154
148-172
136-181
150-174

Is this the version that you are talking about?

Looks like I may have to go into the VCO & add a pad for extra capacitance.

Thanks,

Tim
User avatar
n7maq
Posts: 1440
Joined: Tue Nov 27, 2001 4:00 pm
What radios do you own?: Mocom 70 w/scan!!

Re: VHF X9000 down to Ham Frequencies

Post by n7maq »

I doubt it's the same one. Mike B is the one who knows that RSS the best. Hopefully he will add more.

Tim wrote:Hi Jim,

I've used a version of the RSS that allows programming from 136 - 181.
(that's one of the selections when you create the plug).
The others are:

136-154
148-172
136-181
150-174

Is this the version that you are talking about?

Looks like I may have to go into the VCO & add a pad for extra capacitance.

Thanks,

Tim
WB6NVH
Posts: 266
Joined: Tue Apr 19, 2005 5:08 pm

Re: VHF X9000 down to Ham Frequencies

Post by WB6NVH »

The amateur band RSS is RDPROG Ver. 5. Unfortunately it doesn't necessarily allow the VCO to work properly on the lower end of the 2 Meter band because this is also a hardware issue, not just a software one.

I had some which would transmit down to 144.5 and some which wouldn't transmit lower than 148 without VCO mods (even when using the ham range RSS.) The receiver VCO seems willing to always lock as low as you'll need it.

The receiver front end is basically deaf throughout the 2 meter band without retuning. I retuned mine to something like 144-159.9 and got about 0.3uv/20db.

You can't just select a different frequency range and use the regular RSS because the hardware does not match it. To solve the problem, locate Ver. 5 spl RSS and retune the front end. Bruce Lane up in Washington, a member here, can retune the front end for a nominal fee as well as whatever you might need on the VCO, if anything.
Tim
Posts: 448
Joined: Wed Mar 20, 2002 4:00 pm

Re: VHF X9000 down to Ham Frequencies

Post by Tim »

Thanks for the info.

I have Version 4.00SP05, as well as several others.

I have an x9000 that I've been using for about 10 years &
didn't have any problems with it locking up under transmit
in the ham bands. Re-tuned the preselectors & it worked
about like yours did.

On the new rig, I added some pads in both the TX & RX VCO,
but it didn't seem to change anything. Found a document
on converting the x9000 on 'onfreq.com' & will dig into that.

thanks,

Tim
User avatar
n7maq
Posts: 1440
Joined: Tue Nov 27, 2001 4:00 pm
What radios do you own?: Mocom 70 w/scan!!

Re: VHF X9000 down to Ham Frequencies

Post by n7maq »

Tim wrote:Thanks for the info.

I have Version 4.00SP05, as well as several others.

I have an x9000 that I've been using for about 10 years &
didn't have any problems with it locking up under transmit
in the ham bands. Re-tuned the preselectors & it worked
about like yours did.

On the new rig, I added some pads in both the TX & RX VCO,
but it didn't seem to change anything. Found a document
on converting the x9000 on 'onfreq.com' & will dig into that.

thanks,

Tim
The Version that I was using to put in thew range 1.5 VCO settings is R05.05 SP. I have done several with it and have NEVER had to mess with the VCO for full two meter coverage. I did test a few of my own well below 144MHz with no problems with the unmodified range 2 VCO.
After the codeplug was created I would then use the R6.00 SP for the 255 mode support.

I did have to re tune the RX front end on them, and if you want full RX coverage (I had lots of 154, 155, and 161MHz freqs) it's best to sweep tune it.


Jim

Jim
Tim
Posts: 448
Joined: Wed Mar 20, 2002 4:00 pm

Re: VHF X9000 down to Ham Frequencies

Post by Tim »

Hi Jim,

Checked two of the three that I got (the 1st having vco issues), and
looks like the guy I got them from had some fun with a tweaking tool!

Does anybody have the sweep/tuneup procedure for the VHF x9000?

Includes tuning the 3-pole injection filter into the 1st mixer.

Thanks,

Tim
kc7gr
Posts: 1027
Joined: Wed Mar 13, 2002 4:00 pm
What radios do you own?: Motorola, Icom, Sunair (HF).

Re: VHF X9000 down to Ham Frequencies

Post by kc7gr »

The tuning 'procedure,' such as it is, for getting the preselector down into 2 meters is pretty much:

--Hook your spectrum analyzer and compatible tracking generator together.

--Hook the output of your tracking generator to the radio's antenna input (you may have to temporarily bypass the preamp, if your radio has one).

--Hook the input of your spectrum analyzer to the output lead of the preselector, where it goes into the first mixer board (you have to remove a small cover to do this).

--Adjust your tracking gen output to 0dBm, set your frequency sweep for around 138-170, and retune the slugs for the smoothest bump you can get which covers the ham band. What you're aiming for is to lose some of the high end coverage in favor of the low end. Trust me, you're not going to be able to get the entire 138-170 spread. The preselector was never designed for it.

As for the injection filter, I've rarely (if ever) found it necessary to tweak.

If you lack the appropriate test gear or skill to do this, I can do the realignment for you at my normal rates. PM if interested.

Happy adjusting.
Image
Bruce Lane, KC7GR
"Raf tras spintern. Raf tras spoit."
Tim
Posts: 448
Joined: Wed Mar 20, 2002 4:00 pm

Re: VHF X9000 down to Ham Frequencies

Post by Tim »

Hi Bruce,

Thanks for the procedure!! I shouldn't have any problems with it.

It's obvious that the guy did some tweaking on the injection filter
as well. Do you just peak for max?

Thanks,

Tim
User avatar
n7maq
Posts: 1440
Joined: Tue Nov 27, 2001 4:00 pm
What radios do you own?: Mocom 70 w/scan!!

Re: VHF X9000 down to Ham Frequencies

Post by n7maq »

Tim,

Here is some links to Mike B's web site. There is some very detailed info, more so than in some of the service manuals.

http://onfreq.com/syntorx/syntorx/efreqx.html#ef_adj This will go into the RX adjustments.

http://onfreq.com/syntorx/syntorx9k/con ... tml#x9kefm This talks more about the VCO and ways to extend/shift the freq range.

http://onfreq.com/syntorx/index.html the main site.

Enjoy.


Jim
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