Wednesday, December 1, 2010

FREEBAND/WIDEBAND/MARS-CAP MOD FOR YAESU VX-7r

If you own a Yaesu VX-7r and feel the need to enable wideband TX/RX - Here's how!
Please note that there are several different models on the market, and you will need to choose which mod suits the model you have.
After modification, the VX-7r has a VERY wide TX range, and therefore it is up to you to display common sense to ensure that you don't transmit on bands for which you are not authorized!
Also note that the modifications will take the radio well outside of it's specification, and may put the finals under significant stress, especially if transmitting into an untuned antenna (eg. the stock rubber-duck is no use at 150+ or 455+MHz).
You undertake the following mods at YOUR OWN RISK!

That said, I have done the mod to my own VX7r with no problems at all

Picture courtesy of XU7ADQ Flickr

Picture courtesy of XU7ADQ on Flickr



VX-7r (USA Version)


Author: Rick Jones -
  1. Remove the battery pack.

     
  2. Remove the sticker/cover seal for the pressure sensing unit (SU-1), in the battery compartment. This is the black strip above cellular warning label and is where the SU-1 option goes (see XU7ADQ's pictures above).

     
  3. Locate row of eight jumpers. They are numbered.

     
  4. For Mars/Cap, remove solder jumper 5.

     
  5. For Freeband, remove solder jumper 4 and 5.

     
  6. Reset microprocessor. (Press and hold in the 4, band, and v/m keys while turning the radio on. (alternative reset method is shown below)

     
  7. ENJOY
TX Frequencies:
Freeband: 40-224.995Mhz and 300-579.995Mhz
Mars/Cap: 50Mhz-54Mhz, 140Mhz-174Mhz, 222Mhz-225Mhz, and 420Mhz-470Mhz. 


EUROPEAN/EXPORT (B1 VERSION)
This is to inform you about the European version VX-7R modification. I own the B1 European/Export version (Label outside the box indicates DST:EXP / TYP:B1). Prior to any modifications the transceiver’s jumpers was soldered on positions 2,4,5,7 (factory setting) and the unit was capable of working on the following frequencies ONLY!
- 50-52MHz (RX ONLY, NO TX Possible!)
- 144-146MHz (RX/TX)
- 430-440MHz (RX/TX)
Reception was NOT possible anywhere outside these limits!

In order to modify it you should:
- Unsolder every jumper
- Reset the transceiver by holding down MON/F + HM/RV + Internet Key and power up the transceiver. This will display the Vertex Standard logo instead of Yaesu. Bear in mind that resetting the transceiver by using the method for the USA version (holding down 4 + BAND + V/M and powering up the transceiver) WON’T work! It will just enter a curious set up:
- RX on all bands
- No WX Channels
- Menu Item Misc Setup 20: BEAT SQL (Instead of WX Alert)
- Menu Item Special Memory 6: JR (Instead of Marine)
- Menu Item Misc Setup 17: Japanese (Instead of English)
- Transmission on 40-224.995Mhz and 300-579.995Mhz

After the aforementioned modification you will have continues RX coverage from 504KHz up to 999MHz (including analogue cellular frequencies - NO GAPS!)

Many thanks to Simeon Leriou, SV2GNM for his patience and his will.

73’s to all.

6 comments:

  1. hallo, i am from indonesia
    i like to modif my vx 7R, i have read your posting, but after i seen my vx 7R it is new from store, i never modif it, then i show the jumper 4 and 5 is opened, but the jumper 2 is closed,is that any diffrent for usa version and indonesia version, thanks.

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  2. Hi Edwin, I have the VX-7R DST:EXP TYP:B3, i have not yet done the mods but intend to, if anyone can help or advise on what to do i would appreciate it :)

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  3. Hello all right? Could you tell me if the mode freeband USA, works perfectly RX and TX on 40-50 mhz? I'm looking for that answer for a while and did not find, if you can answer me I will be very grateful!
    Thank you!

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  4. I have done mods on European model,
    but now reception on main band is very bad (low sensitivity)
    Anyone know the reason or solution to this problem?

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  5. Hi, Mike did you ever get an answer to your main band sensitivity issue, as I have the same.

    ReplyDelete
  6. Hi, i am from indonesia
    i like to modif my vx 6R, i have read your posting about vx 7R modification , i never modif my vx 6R, How I can modif my vx 6R and what I must to do, Can the vx 6R after the mod transmit in range 350 Mhz? thanks.

    ReplyDelete