HTX-10 freq expansion with resistor?

[Copake12516]

I will answer that with a definite yes.
The 257 and it's clones are meant to be expandable cb's. The HTX-10 was designed ground up for 10 meter operation. So many electronic differences though some subtle, make the 10 a performer for what it is made for. In side by side comparisons, you can really see a difference in a quieter receive and audio transmit. I did a side by side with both on and tx'ing on same antenna using a switch, both stock mics and reports were all in favor for the HTX-10. I'm not saying the 257 is not a good radio. It is great in my opinion & that's why I own one. Just for strict ten meter operation the HTX-10 is a better build sibling with components different than the 257. It would be an undertaking to do a part to part comparison. But I think that if any radio does what you want it to and performs the way you like, then that's the best radio for you. We all have made the mistake of getting a radio we had high hopes for and been disappointed when we tried it at home. But then we still have that old radio that's like an old friend we can always count on. Whether it's a Kraco or a Lincoln, it's what always worked for us.
Rich

 

[dd18]

Thanks Rich, I thought that might be the case but we don't see many HTX-10's out here....

 

[Wiskey Delta-40]

uses the same chip only with different program, LC72322 by sanyo, fairly common chip, capable of up to 150mhz operation.

Problem is, the software permanently encoded on the prom, "sys 205" limits chip to 28-29.7mhz.

If only I could find a supplier of this chip in small quantities.

Its a little out of my league but I have friends who could reverse engineer the sys 204 (magnum 257) chip and upload the data into a file to be copied, then its just a matter of blowing the data to the new (bootleg) LC72322 chips.

of course it takes quite a setup and skill to solder a 80 pin smd. With the magnum and its cousins going for $200-$250, screwit I will just get a 257 unless someone finds a crate of LC72322 chips with system 204 burnt into them collecting dust in the back of some warehouse somewhere.

There is some kind of mod for this radio......... for there is one on fleebay showing freq 27.165 closing date 10-18-2011, Possible like earlier post that it has had chip reprogram done to it

 

[towerdog]

Yeah,he swapped the chip with one out of a Magnum 257.
You know of someone producing the chips again let me know.

 

[JustinDePolis]

wow---didn't know there was a market for this. The radio can be expanded and not by changing a chip. Did many of them back in the day before the shop closed.

 

[Wiskey Delta-40]

Well then PLZ explain yourself

 

[Tucker442]

Let me ask a question please after reading this you are saying that the HTX10 does not convert like the the old 257 or the Titan Road Pro?? Like remove the diode and short the pins for a radio that have A channels to like H channels??

 

[cryptograph]

wow---didn't know there was a market for this. The radio can be expanded and not by changing a chip. Did many of them back in the day before the shop closed.

Are you talking about the two soldering pads or the four pins that ship with jumpers?

...because I've been playing with the pads a little bit, but I only have so many 10 Ohm resistors....

Playing with the pins coming next.

 

[Tucker442]

I'm talking about if your looking at the back of the PLL board with the front of the radio facing away from you on the 257, Titan Road Pro and Superstar 4800 there are 2 shiny spots to the upper left, once the diode is removed you short those 2 pads and the radio will turn on on 29. something but you get the a through A through I think it's J channel banks, E is the 11 meter band

 

[TonyV225]

Ive never seen one of these that were modded for the 11 meter band but have talked to people (who have heard or again talked to people that said they have did it or seen it done) Ive personally never seen it done and theres a friend of mine thats really good with this stuff and he has 2 HTX-10 mobioles still in boxes brandnew hes tried selling to me. Ive been thinking about buying them for 10 meter mobiles for the kids to use in their vehicles instead of exspensive HF rigs while they are in Highschool I mean you know how kids are.

My buddy bought out a local Radio Shack when they were clearencing their Ham equipment when they decided to stop production. I bought 2 of the brandnew in the boxes little dual band HTX-245 HT's for the kids 2 years ago from him.

 

[Tucker442]

Well it seems every thing I read says they can't be modified without a lot of work, that the PLL chip is not the same as the magnum 257 or the clones

 

[colorburst]

The SMT chip I could solder and/or de-solder if I had to (it takes a special solder tip with a square "hat" to take these off) but the problem with the radio is that the PCB holding the chip is soldered perpendicular to the main board. The result is the main board partially covering the chip which makes it impossible to reach the chip with the proper solder tool; the main board is in the way.
Of course one could first desolder the front PCB from the main PCB, that gives free access to the chip once the boards are separated. But for doing this, one would have to break the black adhesive globs as well that were put there by the manufacturer to reinforce the joint holding the boards together.
To summarize: The whole endeavour is most likely going to result in disaster.
Another issue is the "reverse engineering" of the code from the Magnum that someone mentioned. I am almost 100% sure the manufacturer has set the lock bit after programming, meaning the code can not be read out any more after that. Practically all manufacturers do this nowadays with programmable chips holding firmware, afraid as they are for the never sleeping Chinese copy cats.
So forget it; it cannot be done. Not that it matters; the HTX-10 is an excellent performer on 10 meters to begin with. Just get your ham ticket and enjoy this radio on 10 meters . Band is wide open now (Jan 2012)

 

[Tucker442]

sure wish this knuckle head on the radio could read this, he has been messing with one of these for about 3 months now and just can't get it to work on 11 meters, he also has a HTX 100 that he said he is going to modify for upper lower and AM 11 meters I don't think so:bdh:

 

[K2MAZ]

Anyone successfully done this mod?

KB2LJJ Radio Mods Database and Manuals

Thats the only place i have seen this mod published. Its not on mods.dk, nor defpom except a link on thier forums to same.
Some people say it uses a different chip than its cousins like the Magnum, cannot be modified for expanded coverage, except KB2LJJ mod.
Is this mod total b.s., does it work with early production models or all of them?

pads where there could of been 2 pins for a jumper plug (like the 2950's)you will see one side goes to a smd. and the other goes to a ground island solder a resistor 10 ohms across pads (the resistor is brown black black gold 1/4 watt)


I tried, no luck. I would like to see photo of mod. I'm not sure if I located the correct pad, to solder resister.
Thanks 73

 

[Radio Tech]

This mod will not work. nor does it blow your radio. It does nothing