Why So Few Kits above 20M?

[cockpitbob]

I'm enjoying my Ten-Tec R4020 but wishing I had something that would do 15M or above.  Lots of good DX happens above 20M, and the antennas are conveniently short. 
I think the Weber Tri-Band is the only multi-band that offers bands above 20M.
For me the MFJ9200 series doesn't count since you have to open the case and plug in a different $30 module to change bands.
So why do most of the multi-band (trail friendly) kits only offer some combination of 80/40/30/20?

[KK0G]

I'd say it's a combination of supply and demand plus propagation. Generally 40, 30, and 20 meters are open to somewhere close to 24 hours a day during most of the solar cycle so they tend to work well at QRP levels. Although most 80 meter antennas are far from trail friendly, the band is usually great for close in contacts. Above 20 meters the bands tend to be very dependent on solar activity and can be just plain dead for days or sometimes weeks on end. TFR rigs are always a compromise, the more you stuff in them the bigger, heavier, more expensive, more complex they get, and the more current they draw. A good compromise is to eliminate the bands that are usable the least amount of time.

[gil]

I think it is a matter of design, not supply and demand. The higher the frequency the higher the IF frequency needs to be for mixing. That's hard to do as components are more expensive but also weird problems start to appear at higher frequencies, like component leads and PCB traces interracting as capacitors, antennas and inductances... It gets weird above 30MHz...

Gil.

[Jim Boswell]

15meters CW has always been a favorite of mine. For portable opps, the higher bands make antennas a lot smaller and the closer you can get to 1/4 wavelength the more efficient the antenna. Too bad this solar cycle has not been a "hot" cycle. As a rule I use only 20meters for portable opps. 40meters require too big of antenna and it is hard to make contact with 40meters SSB.

[gil]

15meters CW has always been a favorite of mine.

Indeed... I have noticed that 15m sometimes yields surprising results, getting into areas I usually don't get into... It doesn't always work but when the band is open it's anyone's guess who you'll be able to reach...

Gil.

[Jim Boswell]

Gil, I intended to say 40meter lowpower SSB. Another advantage, 15meters tends to have lower noise level. One more point, 40meters CW requires a narrow CW filter on most radios. 73'S KA5SIW

[KK0G]

Most of us are pretty well aware of the differing technical characteristics between HF bands; likely propagation paths, noise levels, day/night and seasonal changes, etc. What I find interesting is how they seem to take on more 'personal' characteristics and that we as hams tend to gravitate towards them for those reasons even though technically a different band might be a better choice under particular circumstances. I reckon that's why it's a hobby. :)

[Lamewolf]

The reason is because getting a simple radio design to be stable at those frequencies, and the higher you go in freequency, the less stable a simple design will be.  To make them stable needs a very complicated circuit which makes them more expensive.  MFJ has thier Cub in 15 meters but I hear it has stability problems and it requires a lot of modification to get it stable.  I have the 40 meter Cub and its a decent little rig and I have been debating on getting one in 15 meters for a long time but haven't because I also have a Yaesu FT-817 that covers all bands.

[Lamewolf]

15meters CW has always been a favorite of mine. For portable opps, the higher bands make antennas a lot smaller and the closer you can get to 1/4 wavelength the more efficient the antenna. Too bad this solar cycle has not been a "hot" cycle. As a rule I use only 20meters for portable opps. 40meters require too big of antenna and it is hard to make contact with 40meters SSB.

Its not hard to make SSB contacts on 40 meters, my longest contact on 40 meters was to Australia - about 10000 miles using 10 watts SSB into a homebrew vertical that was nothing more than an old 11 meter vertical that I added a resonating coil to the bottom of it to make it resonant on 40.  I do CW and SSB contacts at low power all the time on 40 with my Icom 703.

[RadioRay]

that 703 is an excellent radio.  I cannot believe that they stopped making them.  The receiver is very good.


>RadioRay ..._  ._

[cockpitbob]

I hate to admit this, but this weekend I was part of the rediculous cacophony called the ARRL CW DX contest.  I only made 15 Q's but learned a lot.

Normally 95% of my time is spent between 20M and 40M but during this contest all of my DX contacts were on 10M & 15M.  Now I'm thinking of a Weber tri-bander with 40/20/15.  I would love a do-it-all FT-817 but they are jut a bit big, heavy and power hungry.  I still need to give that some thought.  I don't want to end up with 5 QRP radios, which is the direction I'm heading. 

[gil]

Weber tri-bander with 40/20/15

That is a great combination.. The Elecraft K1 is great also, but more expensive. If it had a DDS VFO I would have kept mine.. I hope the new three-band Weber MTR (supposedly coming out in April) will have 15m, but I doubt it; probably 20/30/40. The Tri-Bander is of course easier to build if you have problems with tiny surface-mount components. I kind of like it better because you don't have to cut leads, just position and solder. The ICs are hard to solder though.

Gil.

[KK0G]

I don't want to end up with 5 QRP radios, which is the direction I'm heading.

Resistance is futile, just let it happen. 8)

[cockpitbob]

I don't want to end up with 5 QRP radios, which is the direction I'm heading.

Resistance is futile, just let it happen. 8)

;D  I just added to your S-meter. ;D

[cockpitbob]

I had to send my FT-857 into the shop.  Except for FM, it turned itself into a QRP rig only able to put out 5-10W on all HF bands.  I was probably using it for 2-3 weeks before I looked at the current meter on the power supply.  I worked a lot of Dx with it that way 8) .  So, now I'm using my R4020 (40/20 meter) 4watt rig.  During the day I REALLY miss the 15 and 10 meter bands.  They seem to be where all the Dx action is during the day.  I keep looking at the Weber tri-bander in 40/20/15.  But then, for about the same as a fully decked-out KX1 I could have a used FT-817.  Sure, it's 2x the size and eats 4x the power, but the damned thing does everything including 2M/70cm.  I have to think hard about how much Dx I'm going to want to do from a backpack and batteries this summer.