From: brian@amd.com (Brian McMinn) Subject: Yaesu 5100/5200 mods Date: Tue, 27 Apr 93 13:56:00 CDT -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Yaesu FT-5100/FT-5200 MODS Rev B (14 Apr 1993) This is a collection of hardware and software mods for the Yaesu 5100/5200 pair. I have the 5100, so I can't verify these for the 5200. I have collected every mod seen on the net (ie. Usenet) since the introduction of the 5100, so I think this list is fairly complete. I am interested in getting updates and corrections to this list, so please send me e-mail if you find something that needs updating. (This includes typos, wrong or missing attributions, caveats, warnings about unmentioned side effects, serial numbers of radios that won't do some of these mods, etc.) SOME OF THESE MODIFICATIONS MAY DAMAGE YOUR RADIO IF YOU PERFORM THEM IMPROPERLY. WHEN IN DOUBT, DO NOT PERFORM THE MODIFICATION. This advice is free, so remember that you get what you pay for. Brian McMinn (brian.mcminn@amd.com) N5PSS 512-462-5389 -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- General Review (5100): Since Yaesu's advertising has already made the good points known, I'll concentrate on the warts and shortcomings. Dual In-Band Receive: works as advertised except for sensitivity. The "main" receiver works very well. The "sub" receiver works very well when tuned to the opposite band from the "main" receiver. When tuned to the same band, the "sub" receiver suffers from slightly lower sensitivity in the ham bands and greatly reduced sensitivity out of the ham bands. There is a 2m VCO/PLL/IF and a 70cm VCO/PLL/IF. I assume that dual in band receive is done with the opposite band's receiver. This would explain the poor sensitivity, but it sure raises some questions about how the duplexer works. I expected a type "N" connector, the radio came with UHF. Control wart: (are you listening Yaesu?) You can only transmit on the "main" (ie. left) side of the radio. When both 2m and 70cm receive are active, you change bands with the "BAND" button. This swaps the left and right displays. When dual in-band receive is active, the "BAND" button changes both the main and sub receivers from 2m to 440 or from 440 to 2m. Arrrgh!!!! I would prefer a "SWAP" button to swap left and right regardless of mode. (The "SUB" button is used instead.) Automatic backlight dim: works as advertised but the backlight level under low ambient lighting is WAY too low. Manual control is the best solution. DTMF page: works as advertized, but the *&%$#@ thing insists on "ringing" like a phone EVERY time it receives the page sequence. This means that you have to co-ordinate with the other station to turn the *&%$#@ DTMF stuff off at the same time or tolerate the "ring" at the start of every receive. CTCSS decode: squelch opens quickly when normal CTCSS decode (an option) is enabled. There is a CTCSS page function that has a distinct delay between receipt of carrier with CTCSS and open squelch. I don't yet understand the use of this "feature." There is no SCAN button on the front panel. Scan is initiated by holding the up or down button of the mike down for two seconds. The scan is blindingly fast when compared to the Alinco 590 that I used to have. Memory: memory is divided into four "banks." Two for VHF, two for UHF. Only one bank can be active for each receiver. I consider this an advantage, but you may not. There are two obvious (to me) uses for this configuration. First, you can store freequencies for different uses in different banks. Second, you can activate one 2m(440) bank in the main receiver and one the other 2m(440) bank in the other receiver and scan them simultaneously. Heat management: After seeing the HUGE heat sink on the back of the Alinco 590, the Yaesu 5100's sink seems too small. In a key down experiment, the heat sink of the Yaesu got almost too hot to touch before the fan kicked on. If I were planning to run a packet station, I would definitely look into some extra forced air over the back of this one. As it is, I'm a bit concerned about how hot it will get mounted in my dashboard. [Others people don't seem to have this problem.] DTMF Decode and Scan: If you have CTCSS decode (an option) enabled on a memory and you are scanning and there is activity on that frequency but without the correct CTCSS tone, the 5100 stops scan, flashes the strength meter and then continues scanning. It is slower than normal scan, but still quite fast. Attributed: Brian McMinn, N5PSS, brian.mcminn@amd.com -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Backlight Control: Effect: manual control of backlight 1) Hold down the MHZ key and turn radio on 2) Use tuning knob to adjust brightness 3) When FUNC is active, the tuning knob will adjust brightness again. 4) You can restore automatic control by repeating step 1. Notes: Manual is fuzzy on this feature. Attributed: Yaesu -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Crossband Repeat (reported as working on 5100 and 5200): Effect: Enable crossband repeat 1) Dial up two frequencies you want to crosslink (be sure to pay attention to transmit offsets, if any) 2) Turn radio off. 3) Hold down the RPT key and turn radio on Result: The tone encode/decode flags and the -+ flags will be flashing and the radio will be in low power mode. When either band's squelch opens, the other band is moved into the primary frequency display and the transmitter keys. Audio link appears to be speaker to mike. Exit crossband repeat mode by repeating steps 2 and 3 above. Attributed: Yaesu -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Transmitter Timeout: Effect: automatically limit transmitter "on" time 1) Hold down the HIGH/LOW button and turn radio on 2) Use tuning knob to change the number in left VFO. This number is number of minutes for the timeout timer. The factory default appears to be 15 minutes. 3) Transmitter shuts off with "Err" displayed in VFO if the time limit is exceeded. Attributed: Bill Mayhew, N8WED, wtm@uhura.neoucom.edu -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Tech Manual: The technical manual for the 5100 is [information wise] pretty spare. No additonal operating notes or hidden secrets are revealed. It is worthwile for the alignment notes and complete parts list. Call the number in your owners manual to order. Attributed: Bill Mayhew, N8WED, wtm@uhura.neoucom.edu -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- DTMF decoding: Effect: display decoded DTMF tones Note: [ed] this works on the FT-530, but not on my 5100. I'm including it here on the chance that it works on the 5200. Please try it on your 5200 (or 5100) and tell me if it works for you. 1) Select frequency and turn on the code squelch 2) Press Function-Page(Code) to select a code memory 3) Dial up to memory #7 [the 5100 won't do this] 4) Watch the dtmf's scroll by as they are heard by the radio! Attributed: jmeyers@ecst.csuchico.edu (Jeff Meyers) -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Crossband Audio Enhancement: Effect: unmuffle crossband audio Connect a 27K ohm resistor between the audio-in and auido-out leads on the data jack (inside the shell of a mini plug, that is). The mic element stays live while in xband operation. It is a good idea to remove the mic from the rig while cross banding if you need/want to eliminate ambient audio. Attributed: Bill Mayhew, N8WED, wtm@uhura.neoucom.edu -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Wireless Mike (review): The wireless mike sends audio over 49.85MHz, so it is can't be used in high RF environments (like near computers). It duplicates ALL front panel controls with the exception of the power button. It interfaces to the rig via a standard mic plug. The receiving unit is only about 1'h x 2w x 1/2d. [ed] The implications of this are that the entire radio can be controlled via the microphone port! Too bad there isn't a fancy *wired* mike with all the controls on it. Several people have reported trouble with the mike -- enough trouble for them to return it because of poor range and poor audio. It works well if you sit on top of the pickup unit, but then you don't need a wireless mike. Attributed: Tony Pelliccio, KD1NR system@garlic.sbs.com -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- The "P" Key on the microphone: I was curious about that "P" key on my FT-5100, so I called Yeasu and they explained the situation. They designed the the mic to accomidate "future products". The "P" key is there to be taken advantage of at a later date by other models. They just did not want to re-design the mic again within a short period of time. Attributed: Will Collier, KB5WRK, COLLIER@gallant.apple.com -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Expanded Receive: Good Effect: enable extended receive coverage New range: 128-180MHz and 420-475MHz Bad Effect: disable automatic repeater shift selection. Warning: This mod does not apply to the FT-5200 as the design is somewhat different. Warning: You must have a very steady hand or else! A magnifying glass would help too. 1) Disconnect DC Power cable from radio. ALWAYS! **Caution** NEVER TRY TO TAKE APART (DISASSEMLBLE) THE FRONT CONTROL HEAD. It will void your warranty. 2) Remove (6) screws from Top Cover of Radio and (6) screws from Bottom Cover of radio. 3) Remove Top & Bottom Covers from Radio (Be careful of speaker falling out). 4) Remove the (2) silver screws on each side of the radio holding front control head to main body of radio. 5) Carefully pull away (a few inches) the Control Head from the radio body. CAREFUL with the Ribbon Cables. **NOTE** There are no numbers on the circuit board so you will have to match up with the diagram below. 6) On the rear of the Control head locate, Unsolder and remove jumper Pad R4072. 7) Solder across jumper pads: R4070 R4068 & R4064 (use wire or 0 Ohm resistor) **NOTE** If you want to change the D/MR button on the microphone to do Band Switching, now is the time. See the next mod. 8) Install Front Control head, Speaker, Top and Bottom Covers and Reconnect Power to the Radio. 9) Press and hold [D/MR] [F/W] [REV] Keys and turn on the Radio. Radio will now show 300.000 & 20.000 on Display. 10) Set UHF Rx Low - Press [MHz] and dial 420.00, press [D/MR] 11) Set UHF Rx High- Press [MHz] and dial 475.00, press [D/MR] 12) Set UHF Tx Low - Press [MHz] and dial 420.00, press [D/MR] 13) Set UHF Tx High- Press [MHz] and dial 450.00, press [D/MR] 14) Set VHF Rx Low - Press [MHz] and dial 128.00, press [D/MR] 15) Set VHF Rx High- Press [MHz] and dial 180.00, press [D/MR] 16) Set VHF Tx Low - Press [MHz] and dial 140.00, press [D/MR] 17) Set VHF Tx High- Press [MHz] and dial 150.00, press [D/MR] 18) Set UHF offset - Press [F/W] then [RPT] dial 5.000 press [RPT] 19) Set UHF tuning - Press [F/W] then [REV] dial 25.0 press [RPT] 20) Set VHF offset - Press [F/W] then [RPT] dial 0.600 press [RPT] 19) Set VHF tuning - Press [F/W] then [REV] dial 20.0 press [RPT] (VHF tuning step varies by state -- many use 15.0) Diagram: [there are no tabs in this section - ed] Ok, here's where it gets tricky, but so you know, a '|' represents a jumper. !Ribbon ! !Ribbon ! !Cable ! !Cable ! ____!J4002 !_______________________!J4001 !_____________ ! !________! !________! ! ! Rear view of FT-5100 ! ! ____ Control Head. ! ! ! ! ! ! !__! | | | | | ! ! | | | | | | | | | | | | | | | | ! ! R R R R R R R R R R R R R R R R ! ! 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 ! ! 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ! ! 5 6 6 6 6 6 6 6 6 6 7 7 7 0 0 0 ! ! 1 1 2 3 4 5 6 7 8 9 0 1 2 1 3 4 ! !__________________________________________________________! Stock US Jumpers After Mod. Jumpers R4001 R4001 R4003 R4003 R4004 R4004 R4051 R4051 R4061 R4061 R4062 R4062 R4064 R4067 <- for D/MR button mod R4068 R4070 R4072 This mod is on Delphi as FT5100.MOD and on anomaly.sbs.com. Attributed: Tony Pelliccio, KD1NR system@garlic.sbs.com -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Band Switching via D/MR button on microphone: Effect: D/MR button on microphone performs band switching rather than D/MR function. 1-5) as in above mod 6) Remove the jumper on Pad R4067 7) skip above step 7 8) continue with step 8 above Attributed: Tony Pelliccio, KD1NR system@garlic.sbs.com -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- [end of mod sheet Rev B] -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- >From jnew@cix.compulink.co.uk Sun Apr 18 05:51:49 1993 Return-Path: Received: from cix.compulink.co.uk by amdcl2.amd.com (4.1/SMI-4.1) id AA13322; Sun, 18 Apr 93 05:51:48 CDT Received: from nucleus.amd.com by amd.com with SMTP id AA11974 (5.65c/IDA1.4.4.1+AMD1 for ); Sun, 18 Apr 1993 03:30:28 -0700 Received: from dvorak.amd.com by nucleus.amd.com (4.1/AMDSN-1.20) id AA07971; Sun, 18 Apr 93 05:27:01 CDT Received: from amd.com by dvorak.amd.com (4.1/AMDSN-1.18) id AA00725; Sun, 18 Apr 93 05:31:52 CDT Received: from cix.compulink.co.uk by amd.com with UUCP id AA11951 (5.65c/IDA1.4.4.1+AMD1 for brian.mcminn); Sun, 18 Apr 1993 03:30:09 -0700 Received: from ben.uknet.ac.uk by ames.arc.nasa.gov with SMTP id AA29892 (5.65c/IDA-1.4.4 for ); Sun, 18 Apr 1993 03:15:46 -0700 Received: from eros.uknet.ac.uk by ben.uknet.ac.uk via UKIP with SMTP (PP) id ; Sun, 18 Apr 1993 11:15:29 +0100 Received: from compulink.co.uk by eros.uknet.ac.uk with UUCP id <24694-0@eros.uknet.ac.uk>; Sun, 18 Apr 1993 11:15:23 +0100 Received: from smtpsrvr by cix.compulink.co.uk id aa24309; 18 Apr 93 9:59 GMT Received: by godzilla. (5.61/25-eef) id AA21961; Sun, 18 Apr 93 10:59:26 +0100 Date: Sun, 18 Apr 93 10:59 GMT From: John Newgas Subject: More FT5200 Mods To: brian.mcminn@amd.com, Jnewgas@cix.compulink.co.uk Reply-To: jnewgas@cix.compulink.co.uk Message-Id: Status: OR Hi there Brian, I was interested to read your FT5100/FT5200 mods. I bought a FT5200 in Florida while on vacation. It wouldn't give the 1750 Hz that is needed in the UK for repeater access. I pestered the local distributor who faxed off to Japan. The enclosed write up was based upon the Information that came from Japan. I would guess that if you want the programming information for a 5100/5200 then a fax to Japan might be worthwhile. On further thought it would be rather nice to get full computer control of the rig when working. Anyway here is my article which you are welcome to include in your text. 73 de John ---------------------------------------------------------------------------- |John Newgas g7ltq@g7ltq.ampr.org [44.131.19.205] - 439.875 MHz | |NTS G7LTQ@GB7XDD.#32.GBR.EUR | Located in Highgate London, N6 | |Internet: jnewgas@cix.compulink.co.uk | Locator Square IO91WN | ---------------------------------------------------------------------------- Yaesu FT5200 Transceiver Mods Revision 2 ======================================== Key Topics: Tone Burst, Extended Frequency Coverage, Cross Band Repeater Part 1 - sourced and written by J. Newgas ========================================= The FT5200 is a Dual band 70cms/2m Transceiver for mobile use. It is sold in different versions for different markets. In particular the USA version has a lower price than the same transceiver in the UK. However it does not have the tone burst button on the microphone working. Function Changes. a) Programming the Control Head It turns out that the functions of pin 5 (the microphone button) can be altered according to which jumpers are made. The instructions for how to access the jumpers is detailed in the ordinary instruction book under the section where packet radio is discussed. Control Head Jumper No Function Required Jumper to be Closed Marked with X on Pin 5 1 2 3 4 5 D/MR X Band X 1750Hz Tone Burst X X Main band Busy Out X Sub band Busy Out X Call Channel X X Main / Sub band busy out - When open SQL = 5 Volt DC Closed SQL = 0 Volt DC Mute Level Selection 1 2 3 4 5 No Mute Minimum X Middle X Maximum X X b) Programming the Interface Unit This is in the main radio case. If unsure of the location refer to the FT5200 Technical Guide. Cross band Repeater Mod 1) Remove (open) JP5017 on the interface unit 2) Press and hold PRI button while switching on the power. 3) The FT5200 will now work as a cross band repeater but the CTSS function will be lost. Extended Frequency Range Mod To obtain maximum frequency range for receive and transmit the interface board jumpers should be modified as follows: 1) Close (short) JP5001, JP5002, JP5003, JP5006 and JP5007 2) Remove (open) JP5004 and JP5005 The frequnecy range possible will now be approximately : VHF Rx 110 - 180 MHz Tx 130 - 180 MHz UHF Rx 330 - 480 MHz Tx 425 - 465 Mhz However you should understand that the alignment will have been done for your original frequency bands and so there will not be optimum behaviour outside these ranges. Broadening the alignment will sacrifice performance at usual frequencies. There seems to be no need in practice to touch the alignment at all. Programming Frequency Limits Having opened up the frequency range you may wish to confine the FT5200 to the areas of interest and legality. a) Press D/Mr , F/W and REV buttons whilst switching on the power b) Program in VHF low edge of Rx VHF high edge of Rx VHF low edge of Tx VHF high edge of Tx Repeat for UHF in the same order. I have not done this so I can give no further advice on this programming General This information came from Yaesu Europe in The Netherlands in response to a specific query about re-introducing just the tone-burst. All such modfications are done at your own risk and will probably invalidate guarantees and other such things. Different legislation is in force in different countries about the legality of owning and operating equipment with capacities outside the licensed bands. You are strongly advised to check this out for yourself to make sure that you comply with the regulations and bureaucracy of your home country. John Newgas (G7LTQ) , 7th June 1992 email to jnewgas@cix.compulink.co.uk ---------------------------------------------------------------------------- |John Newgas g7ltq@g7ltq.ampr.org [44.131.19.205] - 439.875 MHz | |NTS G7LTQ@GB7XDD.#32.GBR.EUR | Located in Highgate London, N6 | |Internet: jnewgas@cix.compulink.co.uk | Locator Square IO91WN | ---------------------------------------------------------------------------- There now follows a second article. I hope that this will clarify unclear parts of my description and give further information which you will find of use. Part II - Further Information sourced and written by Hugo Cornwall ================================================================== ======================================= The following explains how to expand the receive and transmit frequency range of the Yaesu FT-5200 and how to enable the cross- band repeater operation. Carry out these mods at your own risk; you may invalidate any guarantee and, depending on where you live, you may be breaking the law simply by possessing a rig that operates outside the amateur bands. In other areas you may be breaking the law only if you transmit (or in some cases, receive) outside the amateur bands. All the modifications are carried out on the interface board and involve removing or adding links on jumper spots. You will get considerably increased receive and transmit coverage; however, you will lose the Automatic Repeater Shift (ARS) feature. You may think this is an acceptable price. Finally, it should be obvious, but during this procedure you will obviously lose any stored memories. 1 Remove the control head in the normal way and set on one side 2 Remove the upper and lower covers on the main chassis. For convenience, remove the loudspeaker, noting which way the two pin pcb connector is orientated 3 Remove the front of the chassis, that is, the surface with the contacts for the control head. You need only remove the two side screws to do so. 4 The interface board is now revealed and available for work 5 On the right-hand side of the board, locate a double row of ten by two jumper spots, numbered 1 to 20. Some of these jumper spots will be bridged, the precise configuration depending on the area for which rig has been sold. You may like to make a note of the arrangement you can see, in case you wish to re-instate you rig to its original state. 6 The only jumper spots you are concerned with are 1, 2, 3, 4, 5, 6 and 7 for the frequency expansion and 17 for the cross- band repeater. Leave all other jumper spots alone. 7 Using a fine-tip soldering iron, set the jumper spots as follows: 1 closed 2 closed 3 closed 4 open 5 closed 6 closed 7 closed This completes the alteration for frequency expansion. To enable the cross-band repeater - remove the link at jumper spot 17. (Note, just below jumper spot 17 is a separate jumper spot, not part of the group of twenty - leave this alone). 8 Reassemble the radio, including the control head. You must now program in the band limits. 9 Reinitialise the radio by holding simultaneously D/MR, F/W, REV and POWER. The display will now show a blinking "1" in the left-hand memory box and "000.000" in the left-hand frequency display. (Ignore the right-hand display for now). You must now program in band-limits in the following order, VHF rx range, VHF tx range, UHF rx range, UHF tx range. Although you can program in all sorts of bizarre combinations, the rig's rf circuitry of course will only cope with coverage around the "official" bands. The following limits are suggested, but the rig will actually cover slightly less. 10 First, set the lower limit of the VHF receiver. Using either the dial or up-down buttons on the mike, set display at 137.000 MHz and press D/MR button. The blinking "1" is now replaced by a "2". The lower edge of the VHF rx is now set. 11 Now set upper limit for the VHF receiver. Using either the dial or up-down buttons on the mike, set display at 174.000 MHz and press D/MR button. The blinking "2" is replaced by a "3". The upper edge of the VHF rx is now set. 12 Now set the lower limit of the VHF transmitter. Using either the dial or up-down buttons on the mike, set display at 137.000 MHz and press D/MR button. The lower edge of the VHF tx is now set. 13 Now set upper limit for the VHF transmitter. Using either the dial or up-down buttons on the mike, set display at 174.000 MHz and press D/MR button. The upper edge of the VHF tx is now set. (Note: it is possible to set the RX limits wider than the TX limits; for obvious reasons you cannot have the reverse situation). 14 The left-hand display should now read "1" and "300.000" and is now ready for the UHF receiver. The same procedures as steps 10 to 13 should be followed to set UHF rx lower and upper and UHF tx lower and upper should be followed. A suitable range would be 410MHz to 470 MHz. Again full rx/tx coverage is unlikely. 15 If you have made a mistake, or wish at a later stage to vary the various limits, you can reinitialise the radio at any time by holding simultaneously D/MR, F/W, REV and POWER. You must then begin again with step 9. 16 You will find that the pre-set repeater offsets are now no longer available and you will have to set them up manually, using the instructions on p 16 of the manual. The Automatic Repeater Shift (ARS) feature (also on p 16 of the manual) will also have diappeared and you will have no way of getting it back without re-instating the jumper spot links. Cross Band Repeater 17 You can enable the cross-band repeater without altering the frequency coverage. The only hardware alteration is the removal of link 17. 18 To use repeater: Turn rig off in the normal way. 19 Now turn on rig at power switch simultaneously holding down the RPT button. The rig is now a cross-band repeater - you will get confirmation of this from the display: the 100s position on the two frequency displays will be replaced by a "R". The rig will now radiate out on the one band any audio received on the other. The left-hand display shows the transmit frequency - switching is automatic. To return to normal mode, turn rig off and on in the normal manner. 20 Watch that neither of your bands are in repeater mode: the cross-band will still work but you may have difficulty in working out which frequencies you are transmitting and receiving on. While in cross-band repeater mode you can change the frequencies of each band. Try it! 21 The cross-band repeater works better at low power and even better if you use an external diplexer and separate antennas. Better still, use vertical separation for the antennas and, if local conditions permit, cross-polarise the two antennas as well. The problem is of course de-sensing. Alternatively, if you intend operating a remote base, you can use a dummy load for the frequency at which the rig will transmit locally and a proper antenna for the wide area frequency. As with all cross-band repeaters, results will be poor if the UHF frequency is a direct multiple of the VHF frequency. If you are planning extended use of a cross-band repeater, make extra sure that the rig is adequately ventilated. =========================================================================== You will note that there is a discrepancy between the two articles on extended frequency coverage as to which jumpers (4/5) should be altered. I have not perforemd these mods to extend the freqeuncy coverage so I cannot advise. All I wanted to do was to get a tone burst installed! It is quite likely that both work, but may have minor differences between them. My personal opinion is that if you want a wide band receiver then choose a set designed for the purpose. It is however useful to be able to alter frequency coverage for travel between different countries. JRN 28th June 1992