I've recently acquired an Icom IC-745 and I'm unclear on how it's supposed
to work in CW mode. It does receive in SSB and AM, so in general the
receiver appears to work. When I press the 'mode' button to get it to CW
mode, however, it's just... silent

Joel-

As others have already mentioned, the radio might have had the CW filter
removed without replacing a jumper that was removed when the filter was first
installed.

Someone else may have mentioned the possibility of a defective diode in the
filter-selection circuit.

It is also possible that a crystal is bad in the circuit where USB/LSB/CW are
selected. Newer radios use signals derived from the Phase-Locked Loop
oscillator, but older ones had separate crystals for each mode. I don't know
where the IC-745 falls. If you have another radio to tune to the frequencies
of these crystals, you should be able to tell if one is not working. All three
should be within about 3 KHz of each other.

73, Fred, K4DII

I've recently acquired an Icom IC-745 and I'm unclear on how it's supposed
to work in CW mode. It does receive in SSB and AM, so in general the
receiver appears to work. When I press the 'mode' button to get it to CW
mode, however, it's just... silent

Joel-

As others have already mentioned, the radio might have had the CW filter
removed without replacing a jumper that was removed when the filter was first
installed.

Someone else may have mentioned the possibility of a defective diode in the
filter-selection circuit.

It is also possible that a crystal is bad in the circuit where USB/LSB/CW are
selected. Newer radios use signals derived from the Phase-Locked Loop
oscillator, but older ones had separate crystals for each mode. I don't know
where the IC-745 falls. If you have another radio to tune to the frequencies
of these crystals, you should be able to tell if one is not working. All three
should be within about 3 KHz of each other.

73, Fred, K4DII

Be sure the NARROW filter selection is not depressed. I have a 745
also. Great rig!

Steve


On 26 Nov 2004 18:14:40 GMT, unicate (Fred McKenzie)
wrote:

I've recently acquired an Icom IC-745 and I'm unclear on how it's supposed
to work in CW mode. It does receive in SSB and AM, so in general the
receiver appears to work. When I press the 'mode' button to get it to CW
mode, however, it's just... silent

Joel-

As others have already mentioned, the radio might have had the CW filter
removed without replacing a jumper that was removed when the filter was first
installed.

Someone else may have mentioned the possibility of a defective diode in the
filter-selection circuit.

It is also possible that a crystal is bad in the circuit where USB/LSB/CW are
selected. Newer radios use signals derived from the Phase-Locked Loop
oscillator, but older ones had separate crystals for each mode. I don't know
where the IC-745 falls. If you have another radio to tune to the frequencies
of these crystals, you should be able to tell if one is not working. All three
should be within about 3 KHz of each other.

73, Fred, K4DII

Be sure the NARROW filter selection is not depressed. I have a 745
also. Great rig!

Steve


On 26 Nov 2004 18:14:40 GMT, unicate (Fred McKenzie)
wrote:

I've recently acquired an Icom IC-745 and I'm unclear on how it's supposed
to work in CW mode. It does receive in SSB and AM, so in general the
receiver appears to work. When I press the 'mode' button to get it to CW
mode, however, it's just... silent

Joel-

As others have already mentioned, the radio might have had the CW filter
removed without replacing a jumper that was removed when the filter was first
installed.

Someone else may have mentioned the possibility of a defective diode in the
filter-selection circuit.

It is also possible that a crystal is bad in the circuit where USB/LSB/CW are
selected. Newer radios use signals derived from the Phase-Locked Loop
oscillator, but older ones had separate crystals for each mode. I don't know
where the IC-745 falls. If you have another radio to tune to the frequencies
of these crystals, you should be able to tell if one is not working. All three
should be within about 3 KHz of each other.

73, Fred, K4DII

Be sure the NARROW filter selection is not depressed. I have a 745
also. Great rig!

Steve


On 26 Nov 2004 18:14:40 GMT, unicate (Fred McKenzie)
wrote:

I've recently acquired an Icom IC-745 and I'm unclear on how it's supposed
to work in CW mode. It does receive in SSB and AM, so in general the
receiver appears to work. When I press the 'mode' button to get it to CW
mode, however, it's just... silent

Joel-

As others have already mentioned, the radio might have had the CW filter
removed without replacing a jumper that was removed when the filter was first
installed.

Someone else may have mentioned the possibility of a defective diode in the
filter-selection circuit.

It is also possible that a crystal is bad in the circuit where USB/LSB/CW are
selected. Newer radios use signals derived from the Phase-Locked Loop
oscillator, but older ones had separate crystals for each mode. I don't know
where the IC-745 falls. If you have another radio to tune to the frequencies
of these crystals, you should be able to tell if one is not working. All three
should be within about 3 KHz of each other.

73, Fred, K4DII

"Bob Miller" wrote in message
...
Even if the CW filter is missing, he should be receiving CW through
the standard SSB filter.

Just switch to the "CW" mode, and make sure "CW narrow" isn't switched
in.

Thanks Bob, that works! So the problem was that the narrow filter is
missing. :-( Oh well; not that big of a deal.

Thanks to everyone for suggestions.

---Joel

"Bob Miller" wrote in message
...
Even if the CW filter is missing, he should be receiving CW through
the standard SSB filter.

Just switch to the "CW" mode, and make sure "CW narrow" isn't switched
in.

Thanks Bob, that works! So the problem was that the narrow filter is
missing. :-( Oh well; not that big of a deal.

Thanks to everyone for suggestions.

---Joel

"Bob Miller" wrote in message
...
Even if the CW filter is missing, he should be receiving CW through
the standard SSB filter.

Just switch to the "CW" mode, and make sure "CW narrow" isn't switched
in.

Thanks Bob, that works! So the problem was that the narrow filter is
missing. :-( Oh well; not that big of a deal.

Thanks to everyone for suggestions.

---Joel

On Sat, 27 Nov 2004 09:19:59 -0800, "Joel Kolstad"
wrote:

"Bob Miller" wrote in message
.. .
Even if the CW filter is missing, he should be receiving CW through
the standard SSB filter.

Just switch to the "CW" mode, and make sure "CW narrow" isn't switched
in.

Thanks Bob, that works! So the problem was that the narrow filter is
missing. :-( Oh well; not that big of a deal.

Thanks to everyone for suggestions.

---Joel


There's something you might try to narrow the CW bandwidth on your
745:

On my Icom 735, when in the CW mode, and while using the the 2.3 khz
SSB filter to receive CW, the passband tuning knob operates as a
variable bandwidth filter! If I twist it all the way to the right, the
bandwidth is 2.3 khz. And if I twist it all the way to the left, the
bandwidth is narrowed to as little as 800 hz.

I don't know if the 745 works the same way, but you might give it a
try on a crowded CW band and see if there's a narrowing effect.

Bob
k5qwg

On Sat, 27 Nov 2004 09:19:59 -0800, "Joel Kolstad"
wrote:

"Bob Miller" wrote in message
.. .
Even if the CW filter is missing, he should be receiving CW through
the standard SSB filter.

Just switch to the "CW" mode, and make sure "CW narrow" isn't switched
in.

Thanks Bob, that works! So the problem was that the narrow filter is
missing. :-( Oh well; not that big of a deal.

Thanks to everyone for suggestions.

---Joel


There's something you might try to narrow the CW bandwidth on your
745:

On my Icom 735, when in the CW mode, and while using the the 2.3 khz
SSB filter to receive CW, the passband tuning knob operates as a
variable bandwidth filter! If I twist it all the way to the right, the
bandwidth is 2.3 khz. And if I twist it all the way to the left, the
bandwidth is narrowed to as little as 800 hz.

I don't know if the 745 works the same way, but you might give it a
try on a crowded CW band and see if there's a narrowing effect.

Bob
k5qwg