Riveting Signals Mobile on 75M

[WU2D]

I got the ARC-5 mobile station in the car and fired it up this morning in the driveway.
This thing runs around 18 Watts of carrier out into my very inefficient "microhustler".
The good news is that the heavy power run to the battery and the DC filter made of a 20,000 uF, 0.1 uf and 0.01 uF working with a large clamp bead makes the DC sweet as candy. I do have some ignition noise (probably fuel pump related), but it is not as bad as I expected.

The band was is pretty good shape at 7:00 AM with some QSB. The good news is that they heard me - actually even Jamie who was mobile in northern NY heard me. We almost had a mobile to mobile QSO.

But me thinks I need more work on the grounding because I was PW. I will put in a little more work on the station before I head out tomorrow.

Mike WU2D

[WU2D]

Trip Terminus!

I put the ARC-5 station on the road this weekend for my trip to visit my mom in Canton NY(Canadian border). 15 Watts of RF to the MicroHustler snagged me a few contacts on Friday but conditions were a bit rough. I worked N1YTN, Glen and K1QAR Ted in Needham Ma when I was in northern VT. The guys in LI and Jersey heard me but I was light.

I worked Jamie KF2SY who happened to be 35 miles West of me working on some FM station that played Urban Rap to the hillbillies and Amish on northern NY. Ground wave works on 75M mobile! I drove over at 7:30PM in the driving rain and we had an eyeball huddled next to a 4CX3500 FM transmitter. Many scary stories were told.

I headed home early today (Sunday) and worked a slew of stations including KC2JXX, Steve, KA5WHO, Dale, WA1HLR Tim in Montecello, W1HF, WA1SSJ, KF2VMW, NV1H, K1YSK, K1DEU and Dirk. 

Who says low power and a crappy antenna can't work on 75M in the Summer with lightning?

I had a problem with the Heath mobile supply though. It must have a thermal cutout because it kept killing the relay and fill power - not the B+ after it heated up. The ignition noise sucks on the Nissan. Dunno - I will have to do some troubleshooting!

Mike WU2D

[AF9J]

That's a cool setup Mike.  The last time I did HF mobile, was years ago on 10m, with a shortened CB magmount, and a Radio Shack HTX-10.

73,
Ellen - AF9J

[WA1LGQ]

    I like it! Nice setup Mike. Its inspirational. How does the receiver handle vehicle noise?

.........Larry

[WU2D]

Hi Larry!

The ARC-5 had been modified by a conversion artist long ago with a 6AL5 series noise limiter which hides inside but the ignition noise is tough when you are at certain RPMs. And I am not sure that the limiter is actually working at all.

The little box on top of the receiver is a Q-multiplier which is homebrew. I built this unit to see if I could scale the heath 455 kc circuit up to the 1415 kc IF of the ARC-5 - it works great. This unit makes the signals come out of the noise and greatly tightens up the bandwidth and thus it really helps with the noise. Even so, I am not hearing the weaker signals which would be fully copyable if the engine were off.

I talked about the noise with Jamie when I saw him on Saturday. I localized the noise to the ignition harness on the Nissan by waving a loop on the end of some coax connected to the RX and listening with the doors open. Jamie said that I needed to wrap the whole harness with copper tape and ground it. It is too big for ferrite clamp beads.

Mike WU2D

[kf6pqt]

THAT setup is awesome!!!

[Jim KF2SY]

Mike,
I think you have me and Jamie's callsigns mixed up...
Jamie is KF2VM
I am KF2SY.
Although we are about the same age, (I  have more hair).
 I'm not a radio broadcast engineer either...
But if I slept at at a Holiday Inn Express, maybe.
;-)

[WU2D]

Of course I am messed up. Sorry. I had a pad in the car and scriibled.

Mike WU2D