Re: Icom 7400 Problem with Six Metres (SOLVED)

VK4HMW · Post by **VK4HMW** » Sun Jul 15, 2012 4:59 pm

I have a Icom 7400 for some reason has decided to lock out the six metre band just wondering has anybody else heard of or had this problem I called Icom that was a total wast of time and phone call didn't wont to know me I purchased the radio second hand from a dealer in Sydney they couldn't tell anything aswell

if anybody has any idea`s that would be great.... Mark VK4HMW

VK5ZD · Post by **VK5ZD** » Mon Jul 16, 2012 3:44 am

What happens if you tune upwards from, say, 10m? Does it tune through the 6m band?
Can you enter a frequency in the 6m band via the keypad?
Maybe the button that selects 6m if faulty.

73
Iain

VK4HMW · Post by **VK4HMW** » Mon Jul 16, 2012 9:30 pm

Iain thanks for your reply but yes tried all of the above I can enter freq in the six metre band but soon as you key the mic it defaults back to were it was before if you press the button for 50 megs it just beeps at you very weird maybe a software problem or just a piece of junk just cant find out from anybody so far what the problem is .....Cheers Mark

VK2GOM · Post by **VK2GOM** » Tue Jul 17, 2012 8:20 am

Mark, have you done a full microprocessor reset? It will involve holding a combination of buttons down and turning the set on. I don't know which buttons, but the manual will detail it. I have had erratic radio operation before with other radios that has sometimes been solved by a microprocessor reset.

73 - Rob VK2GOM/GW0MOH

VK2AAH · Post by **VK2AAH** » Tue Jul 17, 2012 8:46 pm

I know the IC7000 is reset by turning the radio off, holding the Band Up & Band Down buttons while turning the radio back on. Mine did some strange things & the reset fixed it.

Cheers,

Richard
VK2AAH

VK2GOM · Post by **VK2GOM** » Tue Jul 17, 2012 10:30 pm

For the IC7400, it is (with the set off) hold down [M-CL] and [F-INP] , then press and hold the power on button for 1 second.

Please let me know if this sorted the issue.

73 - Rob VK2GOM / GW0MOH

VK4HMW · Post by **VK4HMW** » Thu Jul 19, 2012 3:46 pm

Rob & Richard Thanks for your reply yes I did try resetting the processor the first time I discovered this but no luck at all I just tried it again no go still so its got me a little stuffed what it could be

weather its a software problem it was working when I first got the radio I did have to get the voltage regulator for the back light on the display replaced at Christmas time weather that's upset it but tech checked out the output on all bands in front me and all was good then so its bit of a puzzle .

Thanks guys for your replies I figure if I put a few feelers someone may have have the same problem its basically the same as IC-746 Pro .

Cheers Mark VK4HMW

VK4HMW · Post by **VK4HMW** » Mon Aug 06, 2012 12:59 pm

VK2GOM wrote:For the IC7400, it is (with the set off) hold down [M-CL] and [F-INP] , then press and hold the power on button for 1 second.

Please let me know if this sorted the issue.

73 - Rob VK2GOM / GW0MOH

Hi Rob thanks for your reply but I did try what you suggested but no luck so its got me a little stuffed what the problem is thanks anyway ....Cheers Mark

VK5KAA · Post by **VK5KAA** » Mon Aug 06, 2012 2:49 pm

hi Mark
you say that you can select 6m rec does it in fact receive 6m.
you press ptt it dies.
then may be you need to look on page V in the manual.
Verify proper antenna has been selected.
incorrect ant socket selected TX would not like that.
i hope that helps i have fallen for that one myself.
Gordon Vk5kaa

VK4HMW · Post by **VK4HMW** » Mon Aug 20, 2012 2:51 pm

VK5KAA wrote:hi Mark
you say that you can select 6m rec does it in fact receive 6m.
you press ptt it dies.
then may be you need to look on page V in the manual.
Verify proper antenna has been selected.
incorrect ant socket selected TX would not like that.
i hope that helps i have fallen for that one myself.
Gordon Vk5kaa

Hi there Gordon thanks for your reply but its no go with 6m you can try hitting the key pad for six metre band but just beeps at you or dial it in but soon as you push the ptt it reverts back to the band you were last on there is 3 sockets for your antenna`s to go to 2 are for hf and six the other for 2m band so its got me baffled or just not a good set and Icom were no help at all they were a little rude I thought anyway thanks again anything is worth a try I guess .... Cheers Mark

VK7DR · Post by **VK7DR** » Mon Aug 20, 2012 3:28 pm

Mark,

If the processor reset doesn't fix the problem... which it obviously isn't.. then you have a malfunction in the hardware.
If the radio works perfectly in all ways then I would suggest that the main unit may not be receiving a 6metre band osc signal.
You can't "set" 6m because it doesn't exist. You can "tune" to 6m but it isn't actually tuning there, which is why it reverts to the channel you were on when you press the ptt.

Other possibilities exist, but they are even nastier.

The radio needs fixing - since it is an ICOM I couldn't be bothered with it, but surely there is someone near you with the skills to set it right.

VK2FRO · Post by **VK2FRO** » Sun Oct 14, 2012 8:49 am

I wonder if the radio has gotten warm enough inside near the band selection resistors/diodes (the same ones pirates use to put radios on 11m), and one of the resistors has fallen off, disabling 6m?

VK4HMW · Post by **VK4HMW** » Sun Oct 14, 2012 5:05 pm

VK7DR wrote:Mark,

If the processor reset doesn't fix the problem... which it obviously isn't.. then you have a malfunction in the hardware.
If the radio works perfectly in all ways then I would suggest that the main unit may not be receiving a 6metre band osc signal.
You can't "set" 6m because it doesn't exist. You can "tune" to 6m but it isn't actually tuning there, which is why it reverts to the channel you were on when you press the ptt.

Other possibilities exist, but they are even nastier.

The radio needs fixing - since it is an ICOM I couldn't be bothered with it, but surely there is someone near you with the skills to set it right.

Hi there Rob .
Well I have just about given up trying to figure it out but I managed to get some help from Icom Aust at first I was told the radio was a grey import and they get grumpy about that but did finely get hold of one of there tech`s and after a bit of dinging in there data bank he found out it was sold by them so that makes it a lot cheaper to fix so if all fails I will have to send down to them to look at I guess just the freight costs are a killer anyway will have a bit more of a fiddle then through out the white flag

you can put it down to the old saying s**t happens I guess thanks anyway for your suggestions I'm going to have a look at one of the reply's suggested and look at the band select diodes see if there is any problems there seeing someone before had open TX the radio which I don't really care much for these days ... Cheers Mark

VK4HMW · Post by **VK4HMW** » Sun Oct 14, 2012 5:13 pm

VK2FRO wrote:I wonder if the radio has gotten warm enough inside near the band selection resistors/diodes (the same ones pirates use to put radios on 11m), and one of the resistors has fallen off, disabling 6m?

Hi there Mr VK2FRO ...
I will have a look at that thanks for the suggestion but I'm nearly at my wits end with it total pain in the butt I bought radio second hand from or friends in Grey stains and yes someone had open TX the Radio which don't care for these days got over that years ago but anyway will have a look at it and see if that's the problem.... Cheers Mark

VK4HMW · Post by **VK4HMW** » Mon Oct 15, 2012 11:44 am

Hi there all I have solved the problem I hope looks like it was who ever did the expand TX/RX mod had left a dag of solder or loosened one of the other diodes maybe for the six mtr band and open circuited it looking out the band so if anybody else has this problem just go look there at the main unit board on the underside of the radio you need to remove what I think is the DSP board which just unplugs under there is the band select diodes or just Google mods for the radio and and they will show you which diodes to look for and were anyway I cleaned them with a old tooth brush maybe it was a dag of solder or a loose diode from the dick who did the mod in the first place and up came 6 mtr band again yipppppeeee

anyway thanks again for all your suggestions and just maybe it might help some other bugger out.
Cheers Mark VK4HMW

VK2FRO · Post by **VK2FRO** » Mon Oct 15, 2012 3:55 pm

Glad the band select diode suggestion worked. These big radios are a bugger to post - and its quite expensive if you want any kind of insurance. Pleased you got your 6m back

Of course this problem should really only occur on a radio thats been opened up. A new one (or an un modified one) should not have this occur. Easiest way to tell without opening the radio is to put it on a dummy load and take it to 11m, and TX. If the radio TX's, the units been modified. Using the 11m into a dummy load should ensure you don't create any interference to more important radio comms (from any RF that may leak from the dummy load)