Found ICOM IC-2350H bug. Need Help
Bill Stewart
While transmitting, the subband receive opens up. It comes through the
speaker quite plainly, and in fact is heard through the mic while I'm
talking, thus re-transmitting whoever is talking on the subband without
their knowledge.
Subband mute functions for both bands are on, and they do mute during
receive. This problem appears only during transmit.
ICOM does not offer direct technical support. Their web page refers you
to your dealer. My dealer says there is no way to solve this problem.
I think it is a programming bug, and wonder if the FCC caught this when
they gave it type acceptance.
For now, the only way around the problem is to turn the volume down on
the subband manually when you decide to rag chew. Then you have to
remember to turn it back up when done or you're no longer scanning and
listening to the subband and you don't know it. That's a load of horse
hockey, and v-e-r-y poor engineering.
Anybody got a suggestion or a mod around this ?
Thanks,
Bill Stewart, N4CRO
ste...@peganet.com
Ken Harrison
>
> I have found a bug in ICOM's IC-2350H dual band radio.
>
> While transmitting, the subband receive opens up. It comes through the
> speaker quite plainly, and in fact is heard through the mic while I'm
> talking, thus re-transmitting whoever is talking on the subband without
> their knowledge.
> they gave it type acceptance.
Hi Bill. What a pain. I'm glad I read about this before I shelled out
the bucks. It really is no different than my dual band HT, though.
I have a question, though. Why do you feel that the FCC should have
caught this during their type acceptance of it? It is a problem that
affects only convenience, it doesn't make it transmit harmonics out of
band or the like. As I understand type acceptance, it is to ensure that
the radio transmits with legal specs -- i.e. deviation, harmonic
suppression, etc...
73,
Ken
N6MHG
Sonoma County Radio Amateurs: http://www.cs.sonoma.edu/~ken/scra.html
David Marc Katinsky
73,
--
dmk
d...@sgi.com N2RDT
David M. Katinsky Systems Administrator/SGI
Jim Fellows
Bill,
Yes this is very annoying and I have not found a way around this. You have not
missed anything that I haven't so at least there are two of us that have this
problem. This is one reason why I'm eargerly awaiting my sevice manual for the
rig from Icom. I'm glad I didn't hold my breath, since I've been waiting since
December of last year. But hey, I waited since Nov 95 for the Z1A serv manual
and it arrived yesterday. So maybe the 2350H one will come soon too!
If I can find a program/hardware mod in those manuals I'll let you know.
Jim
KF6AGJ
In article <31D45F...@peganet.com>, Bill Stewart <ste...@peganet.com> writes:
|> I have found a bug in ICOM's IC-2350H dual band radio.
|>
|> While transmitting, the subband receive opens up. It comes through the
|> speaker quite plainly, and in fact is heard through the mic while I'm
|> talking, thus re-transmitting whoever is talking on the subband without
|> their knowledge.
|>
|> Subband mute functions for both bands are on, and they do mute during
|> receive. This problem appears only during transmit.
|>
|> ICOM does not offer direct technical support. Their web page refers you
|> to your dealer. My dealer says there is no way to solve this problem.
|> I think it is a programming bug, and wonder if the FCC caught this when
|> they gave it type acceptance.
|>
Lewis P. Stephens Jr.
wrote:
>Bill Stewart wrote:
>>
>> I have found a bug in ICOM's IC-2350H dual band radio.
>>
>> While transmitting, the subband receive opens up. It comes through the
>> speaker quite plainly, and in fact is heard through the mic while I'm
>> talking, thus re-transmitting whoever is talking on the subband without
>> their knowledge.
>> I think it is a programming bug, and wonder if the FCC caught this when
>> they gave it type acceptance.
>
>Hi Bill. What a pain. I'm glad I read about this before I shelled out
>the bucks. It really is no different than my dual band HT, though.
>
>I have a question, though. Why do you feel that the FCC should have
>caught this during their type acceptance of it? It is a problem that
>affects only convenience, it doesn't make it transmit harmonics out of
>band or the like. As I understand type acceptance, it is to ensure that
>the radio transmits with legal specs -- i.e. deviation, harmonic
>suppression, etc...
>
>73,
>Ken
>N6MHG
>Sonoma County Radio Amateurs: http://www.cs.sonoma.edu/~ken/scra.html
I have a 2350 and never consider this a bug. I thought that this was to
enable you to minitor another machine or freq. while you were enjoying
yourself in a different location. My Icom W21AT work the same. In the
cases where this actually bothers me, I turn down the volume on the sub
reciever.
Lewis
--
Lewis P. Stephens Jr. KM5BH (Amateur Radio Callsign)
Amber, Inc. CLARC (Clear Lake Amateur Radio Club)
le...@phoenix.net NAMU (NASA Area Macintosh Users)
Lew...@AOL.com
73404.1403.compuserve.com
Joe Dubner
[deleted]
: This is one reason why I'm eargerly awaiting my sevice manual for the
: rig from Icom. I'm glad I didn't hold my breath, since I've been waiting since
: December of last year. But hey, I waited since Nov 95 for the Z1A serv manual
: and it arrived yesterday. So maybe the 2350H one will come soon too!
: If I can find a program/hardware mod in those manuals I'll let you know.
Jim,
I called Icom America earlier this week and ordered a service manual for
my IC-2350H ($35 plus shipping). They implied the manuals were in stock
but they were "running a few days late" and implied they'd mail it in a
few days. We'll see . . .
I hadn't heard of the sub-band bug, but I have plenty of complaints
about the rig's poor third-order intercept performance -- Intermod City!
73,
Joe, K7JD
dub...@spk.HP.COM
Gary Fiber
>Bill Stewart wrote:
>>
>> I have found a bug in ICOM's IC-2350H dual band radio.
>>
>> While transmitting, the subband receive opens up. It comes through the
>> speaker quite plainly, and in fact is heard through the mic while I'm
>> talking, thus re-transmitting whoever is talking on the subband without
>> their knowledge.
>> I think it is a programming bug, and wonder if the FCC caught this when
>> they gave it type acceptance.
>Hi Bill. What a pain. I'm glad I read about this before I shelled out
>the bucks. It really is no different than my dual band HT, though.
>I have a question, though. Why do you feel that the FCC should have
>caught this during their type acceptance of it? It is a problem that
>affects only convenience, it doesn't make it transmit harmonics out of
>band or the like. As I understand type acceptance, it is to ensure that
>the radio transmits with legal specs -- i.e. deviation, harmonic
>suppression, etc...
>73,
>Ken
>N6MHG
>Sonoma County Radio Amateurs: http://www.cs.sonoma.edu/~ken/scra.html
The FCC does not check the transmitter of any Amateur radio, it only need to
meet Part 97 rules. The Amateur Radio which has a receiver that operates above
30 MHz is actually approved under FCC Part 15 as a scanning receiver. Check
the FCC ID AFJIC-2350H and see what the FCC database brings back.
All your habdhelds and mobiles that operate above 30 Mhz are approved as
scanning receivers. The operator interface is not subject to any rules either.
Now for many years the sub band audio is available when transmitting in the
main band otherwise how would you accomplish full cross band duplex operation.
You can not operate full duplex if you can't hear the sub band while
transmitting on the main band. The sub band mute will shut off the sub band
audio when enabled, it does however give a beep if you want that indication.
The service manual will not show nor have any of the CPU programming. It will
only show what the ports of the CPU do.
Gary
Rick McMillion
Are you saying that whatever is heard through the speaker coming from your
sub band is retransmitted out through the microphone via acoustic
coupling? Why would you think that is a bug? That is very normal for
most dual band radio's I've seen. I suppose some of them may have sub
band mute when you are transmitting on the main band, but I know that a
lot of them don't have that feature.
Why not have your mic gain checked/deviation checked, try moving the
speaker, and turn down your sub band audio a bit. I'm sure that you would
be able to find a happy comprimise of mic gain, sub band audio, and
speaker location that will work for you.
73, Rick, WB7UGZ
> Bill Stewart <ste...@peganet.com> wrote in article
<31D45F...@peganet.com>...
> I have found a bug in ICOM's IC-2350H dual band radio.
>
> While transmitting, the subband receive opens up. It comes through the
> speaker quite plainly, and in fact is heard through the mic while I'm
> talking, thus re-transmitting whoever is talking on the subband without
> their knowledge.
>
> Subband mute functions for both bands are on, and they do mute during
> receive. This problem appears only during transmit.
>
> ICOM does not offer direct technical support. Their web page refers you
> to your dealer. My dealer says there is no way to solve this problem.
> I think it is a programming bug, and wonder if the FCC caught this when
> they gave it type acceptance.
>
Bill Nelson
Bill Stewart (ste...@peganet.com) wrote:
: I have found a bug in ICOM's IC-2350H dual band radio.
: For now, the only way around the problem is to turn the volume down on
: the subband manually when you decide to rag chew. Then you have to
: remember to turn it back up when done or you're no longer scanning and
: listening to the subband and you don't know it. That's a load of horse
: hockey, and v-e-r-y poor engineering.
: Anybody got a suggestion or a mod around this ?
Sure, it is simple - but might require drilling a hole in your rig, if
you want to be able to turn the mod on/off.
There are at least two simple mods. The first is to open on lead going to
ohe subband volume control and insert a spst switch with a high value
resistor across the switch. When the switch is closed, the resistor is
shorted, so the volume control works as designed. With it open, the
resistance is in series with the control - muting the receive.
You can also install a relay, tied to the transmit keying line on the
microphone - instead of the switch. Note that if the volume control
works at logic levels, then the keying line could be used with a logic
gate to pull the volume control line either high or to ground, whichever
is necessary to mute the circuit.
Other possibilities such as using a transistor, exist. The above should
provide a starting place.
Bill
Bill Stewart
I too have had intermod problems with the rig in downtown area, probably
from pagers. The ads for the rig say it has special rejection built in
for this problem. Ho Ho Ho. Am thinking of buying a filter I saw
advertised in FLORIDA SKIP for a VHFDN152 from PAR ELECTRONICS. It's
specific to pager frequencies (or can be tuned at the factory) and sells
for $62.00. The problem only gets me going to and coming from work and
only in a specific area, so I am kinda waiting to see just how bugged I
get about that.
I've also gotten word that the rig DOES HAVE the cross band repeater
function built in, it's just not documented. Hold down both main
buttons and the set button until a flashing "l" appears. Hold set
button for 2 seconds to disable. Haven't tried it yet but if true, it
certainly fits with this problem.
Bill
