BEST RIG FER AM MOBILE?

[ve6pg]

...HI FROM TIM...BEEN AWAY A WHILE....WHAT IN YOUR OPINION IS THE BEST SOUNDING RIG,AT LEAST IN STOCK FORM, FOR TRANSMITTING AM?...THERE ARE ALOT OF THESE LITTLE HF RIGS AROUND NOW, AND I'M LOOKING FER ONE FER THE CAR...BE AS CRITICAL AS YOU WANT....TIM..SK..

[Herb K2VH]

During the 50s, when there were lots of AM mobiles around, the rig to have in the car was the ELMAC AF-67, often accompanied by an ELMAC PMR-6 or PMR-7 receiver.  ELMACS do not have "east coast" sounding audio, but they've got lots of it, and a lot of punch.  There are also the older ELMAC A-54s and the newer AF-68s.  But still by far, the most popular is the AF-67.  Contact Mike, N8ECR, who runs an ELMAC net on Wednesday nights.

K2VHerb

[David, K3TUE]

Something to consider:

AF-67: 160-10m
AF-68: 80-6m   <<< seems to my inexperienced self like a set of bands more suitable to mobile

[Pete, WA2CWA]

There were a  number of great mobile rigs from the past that worked and sounded great on AM. With today's autos, under the dash space can be a problem with these "old" rigs.

A great mobile rig that came on the market last year is the Icom IC-7000. All mode, HF/VHF/UHF type rig, with many  of the IC-706 poor sounding audio characteristics removed.



Lots more info, go here:
http://www.icomamerica.com/products/amateur/7000/

[The Slab Bacon]

Another good possibility for an AM mobile, (if you want a vintage rig) You should maybe consider a Gonset G-76. They are a pretty cool little radio (I have 2 of them) 80m - 6m.  Double conversion receiver, 50-70w plate modulated outpoot, whatz not to like!!

                                                                       The Slab Bacon

[WU2D]

If you just want to do 75M, why not a couple of command sets?

Mike WU2D

[KB2WIG]

an/art-13 with a BC 348... load 'em in the trunk and use a C-47 remote controll in the cab...  that'll get you out...   klc

[Steve - WB3HUZ]

BC-610 was designed to be mobile.

[David, K3TUE]

Gonset G-76

I think I'm gettin' me one of these if I ever go AM mobile

[WU2D]

an/art-13 with a BC 348... load 'em in the trunk and use a C-47 remote controll in the cab...  that'll get you out...   klc

Actually the TCS Twins would be better since they are already wired for 12 VDC!

Mike WU2D

[KB2WIG]

                         "TCS Twins "        good call     everything is pretty much a  hand-in-glove equipment.....    'corse, the art-13 spits out 100w without much trouble.... (except for mine)      klc

[w3jn]

BC-610 was designed to be mobile.

My GPT-750 has attachments for shockmounts, so says the manual, for "installation in a mobile environment".

[WA9NQW]

I would like to throw in my vote for the G-76.

Used one in the frat house in college. Got rid of it in the 80's when it was no longer fashionable to have tube rigs. Picked up another about 5 years ago. One of the only plate modulated transcievers that I know of.

73,
Jack
WA9NQW

[WU2D]

Ding!

12 VDC - What about a converted Sonar Marine - now that is a nice AM modulated XCVR and even the power supply is built in. Xtals for 3725, 3880, 3885 and 3890

Mike WU2D

[Herb K2VH]

BC-610 was designed to be mobile.

True, but the generator's a little large to put under your hood.

vH

[Steve - WB3HUZ]

True, but the generator's a little large to put under your hood.

Yea, probably motor home use only.

[ve6pg]

..MAYBE I SHUDA MENTIONED NEWER RIGS,...NO ROOM FER GONSET TWINS, ETC....SK..

[The Slab Bacon]

..MAYBE I SHUDA MENTIONED NEWER RIGS,...NO ROOM FER GONSET TWINS, ETC....SK..

Tim,
          G-76 is not the twins, it is a transceiver. it isnt much bigger (if any) than a modern transceiver unlell you are looking for one of those mini rigs like a 706 or something. A G-76 isnt any bigger than a ts-450 or something of that nature.
                                                       The Slab Bacon

[Pete, WA2CWA]

..MAYBE I SHUDA MENTIONED NEWER RIGS,...NO ROOM FER GONSET TWINS, ETC....SK..

I still like the Icom Ic-7000 although I've used an IC-706MKIIG in the car on AM and it worked OK.
I heard hams using Yaesu FT-897's and 857's on AM but know very little about them.
Yaesu FT-897

Features: http://www.universal-radio.com/catalog/hamhf/1897.html

Yaesu FT-857


Features: http://www.universal-radio.com/catalog/hamhf/1857.html

[N3DRB The Derb]

I remember Tom Wu's mobile experiments and he had a really good setup with a BIG LINYAR big enough to make sparks fly out of his tip of his whip. He still was pisweak on a fixed station scale. I was going to do it but after looking into the effort involved to get a halfway decent signal I bagged it. Might as well just listen I think and get on when one gets home.

[WB2EMS]

"This is just my personal opinion but mobile HF AM operation is usually a waste of time and effort."

I used to operate AM mobile on 75 and 40 meters with a little Alinco DX70 solid state rig and a screwdriver antenna with 102 inch whip on top of it for low bands. I was very pleasantly surprised at the number of contacts I was able to make. I had several long QSO's with Irb, W2VJZ while driving across NY or PA where I'd be in QSO for more than 100 miles, all with 25 watts out of the rig. That was usually in late afternoon or early evening, and I talked to quite a few others if the band wasn't too busy. Daytime on 40 meters was even more productive, I could nearly always QSO with Ashtabula Bill if he was on and many others. When I get the screwdriver rebuilt and back on the current vehicle I will be back to it. Listening was always fun, and despite being a PW little mobile, I had some nice chats.

BTW, back to the genesis of this thread, I would give the DX70TH or one of it's earlier variations consideration. They are usually cheaper than the other small mobile rigs on the market because they are a little earlier design. I see them used in the $400 class. They sound fairly good on AM according to the folks who have given me signal reports. They are simple to operate, not nested menus and all like the ICOMs or Yaesus. I have had mine for years in mobile use and it's been reliable and fun.

You're not going to be loud, even with an amp. But you will be heard and can make QSO's and have fun.

[ve6pg]

..KEVIN..I'M GLAD YOU BROUGHT UP THE ALINCO..I TOO HAVE SEEN THEM PRICED VERY REASONABLE. YOU ANSWERED MY QUERY ABT THE AM AUDIO. I HAVE A YAESU FT847 ON THE FRONT SEAT, ONLY FOR THE TIME BEING. THE AM ON IT IS JUST AWFULL. RECEIVE IS GOOD, BUT TX, FORGET IT. IN A SHORT TIME 10 WILL BE BACK, AND I'VE HAD A GREAT TIME ON 10AM...OK, PLEASE KEEP SENDING YOUR THOUGHTS...TIM...SK..

[WB2EMS]

"YOU ANSWERED MY QUERY ABT THE AM AUDIO."

I was told by none other than WA1HLR that "it has pretty decent audio for a ricebox".
Others mentioned that it had downward modulation, but sounded pretty good despite it. It also has a reasonable width receive filter for AM.

The ICOM 706 uses the FM filter for receive, so it's very wide, about 18 Khz at -6db on my example and you hear about 3 qso's at once and a ton of slopbucket in between. There is a mod to switch in an AM filter FL102 that I did a while back, makes it much better. The DX70 is much tighter, my guess would be about 6khz. Wide enough for reasonable audio, but not so wide that you get a lot of QRM. Also you can hit the narrow button and engage the SSB filter, but you'll have to tune off to the side a bit to get both the carrier and some reasonable highs, so you'll only get one sideband. But that can be useful in QRM. The FT817 and 857 seem to have reasonable receive filters too, but their transmit AM audio sucks, as you've discovered with the 847. The ICOM 706 can make somewhat reasonable audio also if fed through the rear 13 pin jack I'm told, but that might not be practical in the mobile. The 706 generates a transmit spike on key down that overdrives my amplifier at the home station, so it's not a good choice if you are going to run an amp after it.

As far as efficient antenna systems, following other threads in the past, it seems the limiting factor becomes the counterpoise provided by the car body. I've recently been looking into the possibility of a small transmitting loop antenna on 75 and 40. Because they don't need a ground, they get around some of the losses a car body represents, but to build one with low enough losses in the cap and loop is non-trivial. A commercial example is built by QMAC http://www.qmac.com/mobile_antennas.html. I'm not sure how practical a home built unit is, but they claim it is 10 db better than a whip antenna for NVIS work.

[Steve - WB3HUZ]

Whether it's a waste of effort is up to the individual. Everyone has a different risk versus reward equation.

Timtron has been running mobile on 75 meters for decades and I've never had trouble hearing him. I've heard many mobiles on 40 meters that were just about as loud as many fixed stations.

With any antenna low to the ground, you will have ground losses. But if your loop has a higher take off angle of radiation than the typical whip, you should have better signal for the several hundred mile path typical of most AM QSOs on 75 meters. If you get the loop, try to do a side-by-side comparison with a whip. It would be most instructive.

[WB2EMS]

Yes, on 40 meters it seems not to be too hard to put in a decent signal, and yes I've copied Tim while PW mobile a bunch too, and he's always got a pretty usable signal.

I won't be buying one of the QMAC loops anytime soon, they go for $2K+, but have talked to some folks who have built their own loops and had very good things to say about them. Check out K6HPX's loop on his Volkwagon van on his qrz.com page. But you need low loss caps like vacuum variables and big conductive tubing and welded joints, etc to keep the IR losses down below the minuscule radiation resistance of the loops. If you have the tools and the pipe stock, it looks like it can be done, but it's not something you're going to build out of your junkbox. For most of us a good screwdriver or bug catcher is probably the most cost effective.