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Question About Using AM mode on HF

I think the joke was about what frequency the swan users meet on.

The answer was any frequency, because eventually they'll drift on by.
 
Is there actually an inexpensive Collins? Last Collins transmitter I had was a 32V3, sold and shipped it 2500 miles, guy paid a total of $600 for it, and that was nearly 20 years ago :eek:
 
Little or no blower noise
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That's more of a challenge than anything else for me. I don't have the gear to get in the game with these AM guys, but even on SSB it's difficult to get rid of the amp blower (worst offender), the power supply blower, the background air conditioner....
 
moleculo said:
That's more of a challenge than anything else for me. I don't have the gear to get in the game with these AM guys, but even on SSB it's difficult to get rid of the amp blower (worst offender), the power supply blower, the background air conditioner....
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Get a decent noise gate. The Behringer Intelligate (might be a different name) is for the money an amazing unit if all you need is a noise gate.

BEHRINGER: XR2000

A true downward expander/gate will be able to clamp out huge amounts of background noise and do it as transparently as possible.

The big diff vs the simple VOX type on/off switch gates is that they have a gradual ratio for clamping down and opening, which makes them a lot more natural sounding when you clamp them down hard.

A used Symetrix 528e would be a great score for this and give you a mic pre, compressor and parametric EQ in addition to the gate it has.
 
MisterFatty said:
That would depend heavily on conditions, 25 watts is not going to be sufficient to hold a "good qso" on a regular basis, to make contacts, yes...

short occasional contacts are a tad different then what I would consider a "good qso" Guess this all depends upon exactly what wants to be accomplished, but I gathered the OP was interested in partaking in those roundtables with those "Yahoos"

LOL, you must know a different bunch then I do....

Very few modern transceivers are capable of delivering an "excellent sounding signal" on AM, the 101 does a nice job though... You are right though the AM filter in the 101 is only active in RX, and then only after mods.

The audio quality/fidelity that a stock 101 is capable of producing, or any other modern amateur transceiver for that matter is not going to be better "any old tube transmitter ever could" on AM....

while a couple of the most recent Icom offerings are passable on AM, All modern HF transcievers are low-level AM modulation and simply sound like shit... I guess if your half deaf most of what you say could be considered fact. Guess it all boils down to what you consider passable quality, however they shouldn't have even bothered including AM transmit on 99%...


If the original OP is seriously interested in getting into AM I would suggest going on over to The AM Forum - Index, lots of good info, and even a Mod or two for a few modern rigs to improve the AM tx.
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LOL the bunch I know are on the air everyday including right now as I type. The yahoos I'm talking about are the ignorant sidebanders who like to operate right next to AM and then bitch. There are plenty of good people on sideband and a minority of real jerks.

You seem to be confused with what I said. Maybe I didn't make myself clear. I said modern rigs CAN be made to make excellent AM. I did not mean to say that each one already does that. The only new rigs which are excellent on AM out of the box are the Flex radios.

10 meters sucks right now. Not a good idea to recommend it as a hangout at this time unless someone has a good monobander and a lot of time. The guys on 10 AM who are making contacts are the ones with better than average antennas and patience. There is only E skip and extended local work due to late summer type ducting. Sunspots are in the toilet. Yes people are working each other but it's nothing compared to the way it works with sunspots. Most of the stuff heard now is North/South propagation.

If you can't have a meaningful QSO on 80 meter AM with 25 watts it's time to work on your antenna and audio processing. Notice I said to forget the band at night with 25 watts. I never said short occasional contacts. I said to get on late afternoon or very early evening. I did it for years with guess what -...- a 25 watt ricebox. +/- 1dB frequency response from 50-5500cps, able to modulate to 125 percent positive low distortion ricebox. The main reason you need big power on that band at night is to keep other QSOs from starting up on or near your frequency. Low power is a good way to develop skills. Guys who always run QRO are missing out.

Get on and ask Tim Smith how much power he uses during the day.

Everyone knows a brand new Icom isn't going to work for shit on AM. However the stuff made before surface mount and DSP all has excellent potential. Every ssb filter type rig can be modified to use diode switching to bypass the transmit filter. Pipe audio directly into the balanced modulator or increase coupling and decoupling in the existing speech amp. Back off the ALC loop and you have a high performance AM transmit section in your ricebox. I'd rather do that than bulldoze the 810s out of a KW-1 because they are too small by 50% to make full power and modulation. Same for the mod iron. How you gonna hi-fi a Valiant without a hacksaw?

I'd put a completely stock FT-101 up against every commonly OLD available ham type transmitter for ability to fully modulate a carrier and lower audio distortion. The only two I'd leave off that list would be the Johnson Ranger and a Johnson 500 with the clipper filter removed. Most boatanchor transmitters have audio sections that need a lot of work. Some cannot even modulate 100% due to crappy modulation transformer ratios.

A properly modified FT-101 will completely blow away all but the very best modification jobs on a boatanchor transmitter.


4:1 mod iron ratios, tetrode modulators without inverse feedback, modulator tubes spec'ed for only 100% modulation with sinewave, insufficient grid leak bias, poor audio driver circuits which cannot make clean power into any grid current and the main reasons boatanchor transmitters need a lot of help. The simple way to clean up these old rigs is to ignore the entire modulator and use a large solid state power amp connected shunt fed to the final through a large tube type audio output transformer connected backwards.

W3DUQ has been on ham AM for over 50 years all through the AM verses ssb crap. He has experimented with everything under the sun. The guy has more experience with different gear on AM than anyone. Plate modulation, screen modulation, upside down tube modulation, high level balanced modulators, rice burners SDR and lately Flex radios. He was the inspiration for people like the TimTron. DUQ doesn't use plate modulation anymore.

To say low level modulation equals poor quality is just wrong. You are correct that many newer radios have issues on AM. So did the old ones. Apply some work to either to get good sound.

Almost nobody on 80 meter uses a noise gate for very long. There are a few guys who have them dip into the gain slightly. They are not a substitute for better station layout and a directional microphone. Move the final away from the operating position if it's that bad. Use a mic like an RE-20 which has a good enough pattern to point away from noise. Build a quieter final.

I've personally owned and used:

Johnson Ranger Viking 1, Valiant and a 500

Heathkit DX-100, Seneca and Apache

Collins 32V-3

Homebrew 4-1000 X 833s

TMC GPT-750

BC-610F

And a few others. I'd put my current 20 year old ricebox and 4CX1500B final up against all of them for audio quailty. Quality meaning frequency response, ability to modulate the carrier fully and low distortion.

Boatanchors are fun to play with. They are not the only way to go. If you are frustrated to the point of giving up on newer low level radios maybe it's time to hit the books and buy some test equipment.

AMFONE is a great resource. Maybe start a poll of ACTIVE Northeast AM operators there to see whether I'm right about boatanchor use not dominating anymore.

Most important is to get on the air and have fun.
 
I have the W2IHY 8 band EQ and EQPlus, which has downward expansion and noise gate. I don't usually run the noise gate in conjunction with the downward expansion. I can get rid of most of the background noise by getting that along with the gain at the various stages set properly. The biggest problem is that the Ameritron AL800H has a very loud blower and the Heil GM5 isn't directional enough. A mic like an RE-20 or the newer Heil PR-781 is much more directional. Not to mention that the Icom 746 Pro isn't going to cut it on AM...
 
moleculo said:
That's more of a challenge than anything else for me. I don't have the gear to get in the game with these AM guys, but even on SSB it's difficult to get rid of the amp blower (worst offender), the power supply blower, the background air conditioner....
Click to expand...

I've never had that problem, operating with the amplifier running only about 18" from my face and with an air conditioner right behind me. Nobody's ever claimed to hear the noise.

'Course, I mainly operate CW ... :love:
 
Beetle said:
I've never had that problem, operating with the amplifier running only about 18" from my face and with an air conditioner right behind me. Nobody's ever claimed to hear the noise.

'Course, I mainly operate CW ... :love:
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Hook a modulator to that thing....
 

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