Wow, Marcus. Somebody went through a lot of work to find that, and then was nice enough to share it with the rest of us. Great find, although it may need updating now and then.

W0TLP

Thank you for the prompt response.

Indeed, research is key. Everything I am finding is leading me to believe that the easiest way to do this interface is with an older GPS.

I don't plan on using this with a computer. I would like it to be a mobile packet station: transciever, TNC and GPS, nothing more.

I would think that, with the great interest in APRS in the ham community the big manufacturers would pick up on it and release a model or two ready for APRS and give AvMap a little pricing competition.

I use OpenAPRS on my iPhone, which works well but it has a fairly small screen.

I've been considering buying a GPS unit for the vehicle and figure I might as well consider one that would allow me to use it for APRS.

From what I can tell, just about any GPS unit that has an NMEA compatible data port can be used.

The trouble is, I can't find enough details on any current GPS units that support NMEA and would be useable in APRS, other than those made by AvMap, which are beyond my budget and interface with Kenwood radios. I will probably use whatever old HT or mobile I can rig a TNC connection to. I might even just use an old scanner and do receive only.

I'm sure there are are other GPS units out there, I just can't seem to locate them with the detail -- or lack there of -- I see on manufacturer websites.

Any suggestions?

Teak
W0TLP

Felix, I did not see an email address associated with your profile on eham or QRZ. If you would please send me an email the address on my profile that would be great.

Teak

Thanks, guys. This helps.

I think I'll put this charger on eBay for the BMW motorcyclists. I got it at a BMW store -- dang near became a motorcyclist that day! 

I may take Richard's suggestion for the charger. It's more money than I wanted to spend but probably worth it.

My long-term preference is to run it all on solar, but that project is a little farther away.

Teak
W0TLP

I have 6 40Ah batteries to run my shack, which is a single all-band, all-mode radio, a couple of scanners and an LED strip.

The batteries are AGM. I charge them with a CTEK 3300 smartcharger http://smartercharger.com/battery-chargers/#CTEK%20Multi%20US%203300, which I chose because it charges at over 14.7 volts (per the battery manufacturer's suggestion).

Of course, the charger puts off some fairly serious RFI on the low bands. It is bad enough when I am just charging the batteries but if I try to run the rig off the batteries while the charger is plugged in to AC it's way worse.

This noise is most prevalent from 3 MHZ to about 12 MHZ on AM, a little less on SSB. For the ham bands I use, it makes 40 meters almost unusable, 80 meters usable while putting up with the noise.

I have put some ferrite cores on the DC line to the radio and on the AC line of the charger, but I don't notice a reduction in the noise.

I don't see any indication that this charger is FCC Part 15 compliant.

Any suggestions that don't involve getting a different charger?

I am running the shack on a power supply now, which works fine, but I'd love to run it on the batteries.


Thanks

Teak
W0TLP

P.S. This is not related to my previous RFI question involving the low-pass filter and 10 meters. That issue was while I was running on the power supply.

Thanks all.

It turns out the filter was causing all sorts of issues, including SWR that fluctuated with modulation. I removed the filter and everything works fine.

I don't hear the noise I thought I heard.

The noise issue could have been me not knowing what I should or should not hear on the HF bands. I just got into HF a few months ago and had no practical experience with HF before that (even though I had my General ticket for a year). It could also have been something that coincidentally disappeared about the time I put the low-pass filter in the circuit.

So now I am back to my original set up and added a decent speaker, which gives better audio than the radio speaker.

I am pretty sure whatever noise I hear now is just band noise and it's not bad. For a while it actually hurt my ears to listen to 80 meters, but that's just not the case now.

I might try the split ferrite cores on that jumper anyway. Surely it can't hurt anything.

Thanks again for all the feedback. I always learn something here.

I am a happy HFer.
Teak
W0TLP

I was having what I think was some RFI on the low bands, so I installed a low-pass filter, mostly by the suggestion of another ham, just to see if it took care of the issue.

It seems to have cleaned up the noise, although that doesn't make sense to me because I thought the low-pass filter was to prevent me from causing interference, not the other way around. Perhaps I misunderstand how a low-pass filter works. Either way, the extra noise is gone now.

The low-pass filter allows 1.0-30mhz through, but the filtering starts before 30 mhz. As a result, I can no longer use on the 10-meter band. I can't even monitor it.

I am using a single radio with a tuner (the filter is between the radio and tuner) and a 135' OFC dipole. Before I installed the filter I was able to use 10 meters.

Any suggestions for how I can bypass the low-pass filter and still use just one antenna?

A 10-meter antenna isn't that big, I just don't want a bunch of antennas and lines coming in  the house.

I know, I am one of those odd hams who likes minimalism  

Thanks

Teak
W0TLP

Thanks, guys. This helps.

I suspect I'm doing it right -- adjust things until they sound good without destroying my ears or sanity.

As for excessive noise, I'm in the process of determining what may be RFI and what may be band noise. I'm pretty certain some of it is RFI and will work to eliminate it. The power company should be cooperating soon. 


Yep. When I turn the RF gain to the point that I hear nothing the needle points fully past +60 dB. When turned all the way in the other direction -- when I get the most RF gain and the most noise -- the needle drops to zero.


I think that makes sense.  . Either way, I'll try it.

You're absolutely right, Chris. Leadership is critical. I've not experienced enough of these amateur radio emcomm groups to draw any generalization, but weak leadership is pretty much a guarantee of either failure or revolt -- usually both. If an ARES or RACES group is struggling, it's most likely due to leadership. (Although I'll add that even good leaders struggle to lead bad followers.)

One criticism I hear is that ARES leadership is often more about politics than qualifications as a leader. I wonder how common that really is. Leadership in public service (fire/ems/police) is often political but the bad leaders -- no matter the political savvy -- are usually pushed out relatively quickly.

[/quote]

"Real" public service agencies, such as police, fire and EMS departments, do public service events regularly. This might include traffic control, event security, first aid services, letting kids climb on fire trucks, walking around in "McGruff the Crime Dog" costumes and conducting lectures on keeping children safe. The agencies do these events because they are good public relations -- they serve the public by spreading awareness and breaking down the barriers between the public and the public service agencies.

Every time I worked a public relations event and let a kid see the tools on the truck or don my turnout gear, they went nutty with excitement. And the parents thanked all of us -- and showed that appreciation when asked to approve a bond measure or when we ended up transporting a family member to the hospital later. The fire department is respected in the community because the department showed the community respect by participating in community life.

Hams who are interested serving agencies with emergency communications do well to participate in public service such as parades, fairs, marathons, etc. These events afford hams an opportunity to work with their radios in the field, iron out kinks in systems and networks and practice the formal nature of net operations. Such activities also increase public awareness of ham radio and improve relations between hams and the agencies they hope to serve.

Teak

Dear Elmers,

I am new to HF and am trying to better understand the relationship among the RF gain control, S meter and band noise.

I am using the Yaesu FT857d and LDG analog meter set to show signal strength on RX.

I have a fair amount of noise on the lower bands and I'm still learning to identify normal band noise and potential EMF interference, which I believe my station suffers but I cannot yet pinpoint it.

Those noises change as I adjust the RF gain control. When I turn the control fully clockwise I hear more noise but the S meter drops. Conversely, when I turn it fully counterclockwise the noise silences but the S meter raises to the top to +60 dB.

This is counter intuitive to me. It seems to me that when I hear more noise the S meter should be at its maximum, and vice-verse.

Secondly, how do I know where to set the RF gain? It sounds as though my RX audio is cleanest when I can set the RF gain so the S meter points to 9 when I am hearing only noise, no voices. Again that seems counter intuitive to me.

Using the attenuator silences some of the noise I suspect is RFI but of course also reduces strength of desired signals. Playing with the DSP sometimes helps, too, but again too much silences desired signals. The noise blanker makes no difference.

Finally, when I have the RF gain set so the needle points to 9 -- again, that gives me the cleanest audio of desired signals -- the needle doesn't move or fluctuate with the modulation being received. I'm pretty sure it used to, and I could see "+10 dB over 9" now and then. That may have been on 10 meters, where I experience little noise.

Feedback and observations will be greatly appreciated.

Thank you all.

Teak

Thanks, Duffy.  Maybe we can get a K of C net up on 75/80 meters or 40 meters and branch out from there.

Teak
W0TLP

I am suddenly fascinated by the sats. How amazing.

I had the fortune of working AO-51 with a tape measure Yagi before the sat died. Lately I've worked AO-27 and have had some great passes with the Arrow antenna.

I have a few questions about sat work:

What is the the digital noise I've been hearing on AO-27, usually at the start and end of the pass?

Can AO-27 be worked at night? I ask only because I've read that some satellites operate only when in eclipse, which I think means in the daytime. Is that right?

I'll try SO-50 sometime soon. What else should I look for?

Thanks all.

Teak
W0TLP
(Formerly KD0KVV)

I have a Powerwerx SS-30DV power supply and am quite happy with it. It has a small footprint and handles 25 amps continuous  and 30 amps peak. It has Anderson Powerpole connectors built in, so it's perfect to put in a field kit. There are other models that are small and have the Powerpoles.

As SM6XUN mentioned, the power supply you have should handle both radios as long as you don't transmit on both at the same time, which I wouldn't think is likely unless you're running digital and phone at the same time on different bands. You could still listen on one and transmit on the other as the RX consumption isn't likely to exceed 3 amps on either radio. You might be pushing the limits of the power supply a little if transmitting on full power but you should still be fine. There's no reason to transmit on full power unless it's need to make the contact, anyway.

A 50 watt 2 meter radio isn't likely to pull more than about 12 or 15amps at full power, so if you're looking for a dedicated power supply for the VHF rig you might consider one that runs under 20 amps to keep the cost and size down.

Depending on what repeaters you have in the area, you might be better off with a dual-band VHF/UHF radio and just share the power supply until you really feel that you need to separate the power. The dual band radio will give you one more band to play with.

Good luck building the shack. You already have a heck of an HF rig.

Teak
KD0KVV