MARS/CAP mods

[jhooten]

To add to the above:
Commercial and military "full Band" radios are designed with proper filtering and frequency stability to meet FCC/NTIA requirements for the services they are intended. Converted Part 97 intended equipment does not. (some of them barely meet Part 97 technical standards.)

 

[MUTNAV]

Nefarious? I don't know. But, when I see a radio that was originally sold for amateur radio use listed for sale online with a photo that shows the radio tuned outside the amateur radio bands and/or the seller lists "MARS mod" or "modded" as a feature, then I get suspicious of how the radio has been used.

Newer radios usually require removal or repositioning of a very small surface-mount resistor to implement the mod. Watch some videos of these mods being applied and you see some gross soldering skills or diagonal cutters being used. If I'm going to spend several hundred dollars on a used radio, do I want one that has been poked with the infamous "golden screwdriver"?

Even kit radios that have been modified loose their appeal, and I'm guessing the same goes for many other things (cars come to mind). Who wants a canvas that has already been partially painted on (by someone else, not talking da Vinci or anything).

Thanks
Joel

 

[902]

...I get suspicious of how the radio has been used.

I feel the same way about Heathkits. You're entirely at the mercy of how well the person put the device together and calibrated it. Maybe they were sharp, maybe not.

But with MARS modded radios, I would love to get some new member applications from interested amateurs who could commit to becoming active MARS members. The cadre of MARS operators are aging up and younger amateurs aren't backfilling them.

 

[jhooten]

902,

What does MARS even do anymore? I gave up when my traffic count went from a hundred a month to one. That one was my participation report. The nets went from filling the whole hour to doing check ins, a quick training session, maybe a round of comments, then closing at fifteen after the hour. Maybe once a month there would be an exercise where everyone was expected to make up an EEI report and send it on the net just to boost the traffic count.

 

[902]

What does MARS even do anymore?

It's a contingency network.

The traffic nets are still operating. Those are primarily check-ins and some drill messages. Most of the members are assigned to support these, but like you said, the traffic isn't what it was in the 80s when we were receiving messages and providing welfare and morale communications from active duty deployed back stateside. The minimum participation requirement is 12 hours per quarter and one COMEX per year. There are various tools provided for digital communication.

MARSRADIO is different. That's a fairly exciting thing for members who have capable HF stations and antenna systems. My station isn't of the caliber needed to participate in that.

 

[columbas]

Your 100 percent right MMCKENNA, most people are doing this to keep from buying another radio and mounting 2 radios in their vehicle. no matter what the reason your right. So, for me I am not entertaining this idea. It just is not worth the trouble with FCC or having others complain. MERRY CHRISTMAS AND A HAPPY NEW YAR TO YOU AND ALL ON THIS FORUM.

 

[mmckenna]

Your 100 percent right MMCKENNA, most people are doing this to keep from buying another radio and mounting 2 radios in their vehicle. no matter what the reason your right. So, for me I am not entertaining this idea. It just is not worth the trouble with FCC or having others complain. MERRY CHRISTMAS AND A HAPPY NEW YAR TO YOU AND ALL ON THIS FORUM.

To each, their own. I won't do it, either. I have several FCC licenses that I'd like to keep, and one I specifically need until I retire. No point in circumventing the rules to save a few bucks. It's not hard to do things right.

 

[MUTNAV]

Your 100 percent right MMCKENNA, most people are doing this to keep from buying another radio and mounting 2 radios in their vehicle. no matter what the reason your right. So, for me I am not entertaining this idea. It just is not worth the trouble with FCC or having others complain. MERRY CHRISTMAS AND A HAPPY NEW YAR TO YOU AND ALL ON THIS FORUM.

In addition I can't think of any one "opened up" radio that will do better than having an actual C.B, or GMRS radio on those frequencies...

Thanks
Joel

 

[MTS2000des]

Cannot comment on MARS, but CAP's approved equipment list pretty much excludes everything except part 90 certified LMR stuff. So the justification is nothing more than whackerism and the same folks strut around with illicitly programmed trunking radios with cloned IDs with CopSounds (tm) blaring from their hips in grocery stores. Change my mind.

 

[prcguy]

So you say a Cobra or President CB works as good as say an Icom 7300? I don't think so.

In addition I can't think of any one "opened up" radio that will do better than having an actual C.B, or GMRS radio on those frequencies...

Thanks
Joel

 

[JimD56]

In this day and age of 21st-century technology, I agree "MARS/MOD" is straight-up "whackerism".
My agency operates on an analog conventional UHF System that's easily broken into by "Baofung Rangers" often.

 

[MUTNAV]

So you say a Cobra or President CB works as good as say an Icom 7300? I don't think so.

Good question.

I don't have the figures for transmitting, but it would be nice to see how well the 7300 does with out of band transmissions.

Any data would be appreciated.

Thanks
Joel

 

[prcguy]

It does just fine over most frequency ranges and many are used legally on NTIA frequencies.

Good question.

I don't have the figures for transmitting, but it would be nice to see how well the 7300 does with out of band transmissions.

Any data would be appreciated.

Thanks
Joel

 

[alcahuete]

So you say a Cobra or President CB works as good as say an Icom 7300? I don't think so.

Depends on what you consider to be "as good." If you mean overmodulated audio on AM and splattering across half the band, then no, the IC7300 comes nowhere close. You have to remember, that's what 99.9% of the people are looking for with their modded CBs.

 

[sloop]

I don't know about a Cobra CB (their quality has dropped in the last few years), but the President McKinley's CB does hold its own to the Icom 7300 when comparing apples to apples. From the Technical specs from both radios...Icom 7300 sensitivity (10dB S/N) is 2.0 uV; President 0.6 uV. Image rejection Icom 70 dB, President 60 dB. These specs. are for AM. Comparing a $200 President vs. a $1200 Icom is not a fair comparison because you do tend to get what you pay for. I too would like to see the tech. specs. for an Icom operating on an out of band mod.

 

[902]

In this day and age of 21st-century technology, I agree "MARS/MOD" is straight-up "whackerism".
My agency operates on an analog conventional UHF System that's easily broken into by "Baofung Rangers" often.

This is simple. To my knowledge, MARS has no allocations on UHF. There is no UHF MARS modification, and no justification to use it as an excuse.

 

[902]

Cannot comment on MARS, but CAP's approved equipment list pretty much excludes everything except part 90 certified LMR stuff. So the justification is nothing more than whackerism and the same folks strut around with illicitly programmed trunking radios with cloned IDs with CopSounds (tm) blaring from their hips in grocery stores. Change my mind.

From personal experience when I was very involved in the organization, everyone wants a CAP corporate radio and only very few people will turn their radios on to monitor in the background, let alone for nets. It seems to me that the higher up one got in the organization, the more he or she wanted a radio, and the less the likelihood they'd ever turn it on. It was very frustrating. When they did turn it on, "I can't hear anyone!" Well, yeah. YOU are the activity. They expect that it's all-CAP, all the time with non-stop radio traffic, and instead it's crickets.

There was also the, "THEY have one, so WE want one, too!" And that gets stored in a locked file cabinet and only sees daylight during the annual inventory. I wouldn't believe it if I heard someone walking around walking around with one in their back pocket while they were out and about.

 

[prcguy]

A President McKinley does not hold its own, the specs you publish are about as meaningless as comparing cars based on their factory colors like this one is metalflake so it must be better, etc. The image rejection is meaningful where the Icom is 10dB better out the gate. Close spaced dynamic range is where the rubber meets the road and nobody bothers to test CBs for this because its not worth it, but its what costs a lot of $$ in design and engineering. The Icom 7300 has stellar receive performance considering its called an "entry level" amateur radio. It does things that no CB can do and does it much better.

The only place a CB will do better is with AM modulation with aftermarket mics, most amateur radios will not achieve the same level of AM modulation density or sound that a cheap CB can muster up. But on SSB the Icom 7300 will run circles around any SSB CB and its stock hand mic will sound better than most CBs with expensive mics due to its internal EQ and compression settings.

If I get some time I'll do a quick CB vs 10m second harmonic test on an Icom 7300 and I suspect there will be no difference and the Icom will meet full specs on CB since it uses the same filter on both bands.

I don't know about a Cobra CB (their quality has dropped in the last few years), but the President McKinley's CB does hold its own to the Icom 7300 when comparing apples to apples. From the Technical specs from both radios...Icom 7300 sensitivity (10dB S/N) is 2.0 uV; President 0.6 uV. Image rejection Icom 70 dB, President 60 dB. These specs. are for AM. Comparing a $200 President vs. a $1200 Icom is not a fair comparison because you do tend to get what you pay for. I too would like to see the tech. specs. for an Icom operating on an out of band mod.

 

[mtindor]

I'm going to mod my Yaesu FTDX-10 and FT1000MP just to irritate some of you guys

 

[prcguy]

As threatened, here is my Icom 7300 second harmonic from transmitting 100w FM at 28.500MHz and 27.380MHz within the CB band. Peak carrier at the fundamental was not calibrated but the radio is doing about 100w and it was exactly the same power level on CB and 10m, which is within a fraction of a dB of 50dBm or 30dBw, which is 100w. Reference line on the analyzer is 50dBm.

Second harmonic of 28.500MHz is 57.000MHz and the level is 5.19dBm or -44.81dBC. Second harmonic of 27.380 is 54.76MHz and that is 4.77dBm or -45.23dBC. Turns out the radio has better attenuation of the 2nd harmonic when in the CB band and its .42dB better than on 10m. So the Icom 7300 meets better 2nd harmonic specs on CB....

The FCC specifications for a current HF transmitter spurious emissions is -43dBC, so this radio meets FCC specs.

A President McKinley does not hold its own, the specs you publish are about as meaningless as comparing cars based on their factory colors like this one is metalflake so it must be better, etc. The image rejection is meaningful where the Icom is 10dB better out the gate. Close spaced dynamic range is where the rubber meets the road and nobody bothers to test CBs for this because its not worth it, but its what costs a lot of $$ in design and engineering. The Icom 7300 has stellar receive performance considering its called an "entry level" amateur radio. It does things that no CB can do and does it much better.

The only place a CB will do better is with AM modulation with aftermarket mics, most amateur radios will not achieve the same level of AM modulation density or sound that a cheap CB can muster up. But on SSB the Icom 7300 will run circles around any SSB CB and its stock hand mic will sound better than most CBs with expensive mics due to its internal EQ and compression settings.

If I get some time I'll do a quick CB vs 10m second harmonic test on an Icom 7300 and I suspect there will be no difference and the Icom will meet full specs on CB since it uses the same filter on both bands.