Question About Using AM mode on HF

[Beetle]

Hook a modulator to that thing....

Don't need one.

 

[mackmobile43]

My newest baby

 

[W5LZ]

mackmobile43,
I think you are going to eventually find that your new toy is not exactly as good as it could be (that's being as nice as I know how). While they are certainly better than not having one, Kenwood/Trio filters are some of the worst you can find for use in Kenwood radios. I really wish I hadn't found that out by experience.
- 'Doc

 

[HiDef]

Doc, I have one of those 8.83 kc I.F. filters. Tried it in my TS-440 and it was not all that good just like you said. A friend has one in a TS-430 and his narrow filter works very well. I have not tried to figure out why as my rig had better filtering added in the 455 kc I.F. That cannot be done in a 430 because there isn't a 455 kc I.F.

 

[W5LZ]

I think I've had all of kenwood's filters at one time or another except for the 8.3 AM filter. Since all the rest of them have not exactly been very good, I have no doubt that they all are of the same 'quality'. I changed to what's now 'InRad' filters and there was quite a bit of difference for the better! I didn't believe how much difference they made. I can't say why there is that much difference, I've never taken either brand of filter apart to see (probably wouldn't know if I did). I also used the same InRad filters in two different models of radios. They helped in both instances. If thre was an option of an InRad for my present rado I'd certainly get them, but there isn't (yet). Oh well.

And just for grins. If you happen to have a TS-440, and you ever run across one of the tuning rate doo-dads made by InRad, get it! Changes the tuning rate of the main dial to a much 'finer'/slower rate and is well worth the cost. It's a variable rate thingy, spin the knob fast and it reverts to the 'old' rate, spin it slowly and the tuning rate slows down too. Very nice!
If you find one and don't like it, I'll take it off your hands immediately!
- 'Doc

 

[HiDef]

The 440 comes with variable tuning already from the factory. If you turn the knob real fast of flick it with your finger the tuning rate jumps to fast. It works better when the dial tension is turned down. One of the features I like about that old rig.

 

[SR385]

I think that will give him quite a bit wider signal on AM for TX though...afaik the stock filter setup is more like 6k wide.

Factory SSB filters give you a narrower TX and RX and are useful for interference, but the AM filters generally widen you out so you sound better.

At least that is my understanding.

That should give you about 2k wider signal, which is quite a lot more audio information...better fideltiy for sure.

Oh hmmm that's a 6k filter....just looked it up.

 

[RickC.]

Believe it or not, I've gotten good reports from the Southeast guys who run big iron from my little IC-718. It's weird, having to watch the ALC rather than the plate current, but with the compression in and mic gain adjusted just to the point of the ALC scaling back the carrier on the peaks, I run 25W carrier into an SB-200 when I need to, for 125W carrier out. I've heard recordings of my rig off the air on the Tuesday evening net, and can't tell that much difference in it and many of the HT-44s, Valiants, etc. I haven't done anything to the rig or tried to bypass the xmit filter (though it's pretty easy to do with this little ricebox) since I only casually operate AM, but have tried several different mics with it. The AM bunch's favorite? The Heil ICM, which is not my favorite mic, but if those fellas say it sounds best on AM with that rig, then that's what I use.

I have a Ranger I need to get going again one of these days. My last attempt let the smoke out of the HV choke...



Rick

 

[W5LZ]

HiDef,
Sorry, no. The TS-440 didn't come that way, it was an after market option from 'InRad'. If you take the lid off of a '440 and look to the front, if there's a small circuit board 'standing' above the main circuit board on a bent metal connector looking thingy, that particular '440 has the 'InRad' option.
If you know how the main tuning dial worked, then understanding that the option was a "count by 2" circuit will mean something, it only counted every other 'pulse'. (I know that's not the right way to say it, it's just been way too long since I still knew that stuff to remember the correct terminology, sorry 'bout that.)
And speaking of terminology.
Did you know that crocheting and rail roading are a lot alike? Really! You can "hook one" and "drop two" in either one. I find that very interesting. Don't you?
- 'Doc

 

[HiDef]

I think that will give him quite a bit wider signal on AM for TX though...afaik the stock filter setup is more like 6k wide.

Factory SSB filters give you a narrower TX and RX and are useful for interference, but the AM filters generally widen you out so you sound better.

At least that is my understanding.

That should give you about 2k wider signal, which is quite a lot more audio information...better fideltiy for sure.

Oh hmmm that's a 6k filter....just looked it up.

The 8.83 I.F. transmit chain on the TS-440 does not use the crystal filters. They are only used on receive. Every rig is different but most mid 80s on rigs are like this.

The 440 has a really cheap filter in the 455 khz I.F. Bad shape factor and too wide for nighttime operation.

There are mods which completely bypass the filters on transmit. You determine AM audio bandwidth in the audio chain.

 

[HiDef]

HiDef,
Sorry, no. The TS-440 didn't come that way, it was an after market option from 'InRad'.
- 'Doc

Doc! You are thinking of a different radio. I've had my hands on many of these radios. Every one works like I said from the factory. No extra boards. I have seen what you are talking about somewhere but not in a TS-440.

Railroading? Too heavy. I have enough heavy stuff. It gets heavier every day.

 

[mackmobile43]

Is a joke somewhere about where the Swan-net meets, and the Swan 3drifty, but to answer your question without some divine intervention yes they do drift

yes along with its cousin the 1011c siltronix

I have the ts-430 kenwood with the optional 6kc AM filter which is much closer to 8kc and it's an awesome AM transceiver.

 

[W5LZ]

HiDef,
Every one of them that you've had your hands on may do the fast freq change with a fast spin. But what I'm talking about was a very slow frequency change with just a 'normal' turn of the knob. Not a Mhz per rev of the knob, but a 10 Khz change(?), huge 'fine' tune difference. To the best of my knowledge Inrad was the only source for those modules (or actually it was IRC, International Radio and Crystal, at the time, in Florida). That module was the only thing I wish I had kept when my '440 bit the dust. Oh well.
- 'Doc

What ever that rate of change was per rev of the knob, the module slowed it down by at least a factor of 10.

 

[HiDef]

HiDef,
Every one of them that you've had your hands on may do the fast freq change with a fast spin. But what I'm talking about was a very slow frequency change with just a 'normal' turn of the knob. Not a Mhz per rev of the knob, but a 10 Khz change(?), huge 'fine' tune difference. To the best of my knowledge Inrad was the only source for those modules (or actually it was IRC, International Radio and Crystal, at the time, in Florida). That module was the only thing I wish I had kept when my '440 bit the dust. Oh well.
- 'Doc

What ever that rate of change was per rev of the knob, the module slowed it down by at least a factor of 10.

I just tried one. Slowly tuning I got 12 khz per 1 revolution on CW and ssb. AM was 60khz per revolution. If I fling the tuning knob it moves much faster but I cannot tell just how fast per revolution.

 

[W5LZ]

Now think of the 'fine' tuning if that were slowed down by a factor of 10.
- 'Doc