Where are Your VHF antennae?

[N2255D]

Here is mine.

That's the same position as mine and in 17 years never a problem transmitting or receiving.

[bat443]

I had a similar problem with the Narco 810 in my 170 when I had it. I replaced the antenna, then the coax, but neither seemed to help. Then I pulled the radio out of the rack and noticed that the connector on the back had some light corrosion on some of the pins. Cleaned them up with contact cleaner, check it first as the body of the connector may be plastic, and a small brush. The problem was solved. Just something else to check. Just as information, before I pulled the radio I connected an extension cable and a hand held com to my antenna and performance with the hand held exceed 40 miles talking to ground stations from 3000 feet. Hope this helps.

Tim

[GAHorn]

How do you utilize that alphabet-whiz-wheel? (Aren't you glad I didn't ask you anymore questions about preferred positions?)

[paulbritton88]

Thank you for all the helpful comments. Especially, the watch-building types!

I do plan on removing the very old coax and installing rg400, and have a newer antenna I was already planning on installing.
I checked the ground and it seems fine.
The kx170b radio is fresh back from the shop, so I assume it's output is fine.

I should clarify: I can talk to Houston approach, if I turn 90 degrees away.
Just not when I'm pointed at Hobby tower, where their repeater antenna is located.
All the turning makes them nervous

[GAHorn]

Paul, don't assume anything....have the field strength tested.
What you last described sounds like radiation pattern issues, and if you
don't mind the work and already have the materials, go ahead with the cable
and antenna replacement,....
However, ...what was the reason for the radio repair? Was it already failed? Or was
that only for resting?
Ask the shop specifically, what is the output of that transmitter......don't assume
they can read between the lines of your problem.

[paulbritton88]

10 watts

I'll let you know how the changes affect my problem.

[Bruce Fenstermacher]

Just happen to look at the 170A model IPC today and noticed Cessna shows two whip antennas place just about like Paul's when two VHF radios are installed. How about that.

[paulbritton88]

I removed the ancient, tv-looking coax, which had one splice near the instrument panel and replaced it with new rg-58 (the aircraft parts store did not stock rg-400). Then I cleaned up the antenna and connections.

The verdict from Houston Approach, 30 miles distant: "You're scratchy but very readable."
ATIS from a field 50 miles away was 5X4 from 3500' MSL.

I have a transponder and radio: I'm radar vectors equipped.

I'm still going to put the new antenna and RG-400 on, but I'll keep one of the stainless whips for future use... possibly the hand-held.

[GAHorn]

I...The verdict from Houston Approach, 30 miles distant: "You're scratchy but very readable."
....

To get rid of the "sratchy-ness"... Go to WalGreens and get some of that "Monkey Butt" powder.


(I imagine the "scratchy" is your radio, a ground-issue, or a poor microphone/connect.)
Congratulations on finding the bad co-ax and spice. Those old cables and splices really steal transmit power.

[FredMa]

Another often overlooked item you may want to check are the jacks for your headset. Make sure there is good spring tension on the tabs that contact your headset pins and clean your headset pins with scotchbright. These do get light corrosion from handling. cleaning the jack tabs Is not a bad idea either. I have fixed many "scratchy mics" like this and best of all it doesn't cost anything.