Terra TPX 720 battery question

I have an old TPX 720 handheld radio. It was sitting for 20 + years
and the rechargable batteries were shot. They are 1.2 v nicads, 10 of
them. Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? The nicads are 12
volts total, and the dry cells would be 15. I don't want to fry the
radio.

Thanks

Kurt

wrote:
I have an old TPX 720 handheld radio. It was sitting for 20 + years
and the rechargable batteries were shot. They are 1.2 v nicads, 10 of
them. Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? The nicads are 12
volts total, and the dry cells would be 15. I don't want to fry the
radio.

Thanks

Kurt

My TPX 720 manual specifies 10 AA Nicads and operating voltage of 11.8
to 13.7 volts. It also came with a 14 volt DC cigarette lighter charger.
No mention was made about using regular AA cells. If you would like a
copy of the manual in .pdf form, just email me and I will send it out.

--
Peter D. Brown
http://home.gci.net/~pdb/
http://groups.yahoo.com/group/akmtnsoaring/


Going home after a long day
http://farm2.static.flickr.com/1415/...22928754_b.jpg

The fleet at Summit. Mt. McKinley is about 45nm away at 20,320 msl.
http://farm1.static.flickr.com/187/4...cb8d2482_b.jpg

The 170B at Bold near Eklutna Glacier
http://farm1.static.flickr.com/168/4...a216d7bb75.jpg

On Mar 22, 6:51*pm, Pete Brown wrote:
wrote:
I have an old TPX 720 handheld radio. *It was sitting for 20 + years
and the rechargable batteries were shot. *They are 1.2 v nicads, 10 of
them. *Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? *The nicads are 12
volts total, and the dry cells would be 15. *I don't want to fry the
radio.

Thanks

Kurt

Another option would be to hook up 8 of the 1.5 volt dry cells (I know
Radio Shack makes an 8 cell holder), and make a little adapter to go
from that pack to the radio wire harness.

I have two Terra's that are in about the same condition. The previous
owner seemed to think that the radios should be left on charge all the
time so they would be "ready when you needed them." Needless to say,
those NiCads are dead to the world now.

Steve

There is a company in the UK which will make a battery pack for you,
probably for less than the cost of nicads (and use NiMH if you want, which
has to be better!) email http://www.axessinternational.com/ContactUs.asp or
check their website.
1000mAh Icom battery packs are very reasonable from them.


"Steve Leonard" wrote in message
...
On Mar 22, 6:51 pm, Pete Brown wrote:
wrote:
I have an old TPX 720 handheld radio. It was sitting for 20 + years
and the rechargable batteries were shot. They are 1.2 v nicads, 10 of
them. Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? The nicads are 12
volts total, and the dry cells would be 15. I don't want to fry the
radio.

Thanks

Kurt

Another option would be to hook up 8 of the 1.5 volt dry cells (I know
Radio Shack makes an 8 cell holder), and make a little adapter to go
from that pack to the radio wire harness.

I have two Terra's that are in about the same condition. The previous
owner seemed to think that the radios should be left on charge all the
time so they would be "ready when you needed them." Needless to say,
those NiCads are dead to the world now.

Steve

TPX720 uses normal AA NiCad batteries, usually available locally...however,
in nearly all cases (years ago, these have been off the market for a very
long time now) we ended up replacing the battery holder at the same time due
to corrosion.....even if the corrosion was invisible and even if you clean
it there always seemed to be a reduced current and eventually no charge....I
doubt you'll find these cases anymore since they were Terra parts.
The TPX was unique in that it was the only one to TX on more than 1 watt as
a handheld but also offered two very excellent qualities no other handheld
could match....it was the only handheld to also serve as a wheel chock and
it was virtually theft proof! I know of no one who would ever want to steal
one )
tim
Please visit the Wings & Wheels website at www.wingsandwheels.com

wrote in message
...
I have an old TPX 720 handheld radio. It was sitting for 20 + years
and the rechargable batteries were shot. They are 1.2 v nicads, 10 of
them. Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? The nicads are 12
volts total, and the dry cells would be 15. I don't want to fry the
radio.

Thanks

Kurt

wrote:
I have an old TPX 720 handheld radio. It was sitting for 20 + years
and the rechargable batteries were shot. They are 1.2 v nicads, 10 of
them. Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? The nicads are 12
volts total, and the dry cells would be 15. I don't want to fry the
radio.

I've used three TPX 720s over the years, panel mounted, starting in 1980
with the first one in my Libelle, in 1984 the 2nd in my ASW 20 C, and
now 13 years with the 3rd in my ASH 26 E. It's a good radio, with clear
transmission and a sensitive receiver. I've run them all directly off
the 12 volt glider battery.

To test it, you could try 9 AA batteries (about 13.5 volts) and short
the last position in the battery holder. Or, remove the batteries, then
temporarily connect a 12 volt battery to the output leads from the
battery holder. Make sure you get the polarity right.

If the radio works satisfactorily, you can put in new ni-cads to make it
portable again. If it doesn't, there are several good choices for
hand-helds these days at bargain prices compared to what the TPX 720
cost when it was new!

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Tim is right about the corrosion. It is doubtful, but If the case is
still ok, you can get "dummy" batteries from Radio Shack (at least you
used to be able to - they don't seem to have the selection that they
used to) to convert to alkalines. the dummies are available at other
electronics suppliers and probably most places that sell nicad or nimh
cells. Basically, it is a plastic spacer with a conductor to bridge
between the battery contacts on the case. Otherwise, it would be very
easy to cobble something up from the old Terra battery case. It will
most likely need to be rebuilt anyway due to the corrosion. I ran a
couple of Terra's on alkalines, but the corrosion was too much of a
headache. I never got around to rebuilding the battery case.
Ideally, now I would call up Batteries America (formerly Mr. Nicad) or
some other reputable battery shop to put together a battery pack that
would fit in the Terra or just order cells with solder tabs and do it
myself.

I have seen some "nickel-alkaline" rechargeables that are supposed to
retain charge much longer than nimh or nicads. They don't seem to
have the storage capacity of nimh but they are still quite a bit more
than the old nicads. Anybody know anything about them?


On Mar 23, 3:02*pm, "Tim Mara" wrote:
TPX720 uses normal AA NiCad batteries, usually available locally...however,
in nearly all cases (years ago, these have been off the market for a very
long time now) we ended up replacing the battery holder at the same time due
to corrosion.....even if the corrosion was invisible and even if you clean
it there always seemed to be a reduced current and eventually no charge.....I
doubt you'll find these cases anymore since they were Terra parts.
The TPX was unique in that it was the only one to TX on more than 1 watt as
a handheld but also offered two very excellent qualities no other handheld
could match....it was the only handheld to also serve as a wheel chock and
it was virtually theft proof! I know of no one who would ever want to steal
one )
tim
Please visit the Wings & Wheels website atwww.wingsandwheels.com

wrote in message

...



I have an old TPX 720 handheld radio. *It was sitting for 20 + years
and the rechargable batteries were shot. *They are 1.2 v nicads, 10 of
them. *Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? *The nicads are 12
volts total, and the dry cells would be 15. *I don't want to fry the
radio.

Thanks

Kurt- Hide quoted text -

- Show quoted text -

On Mar 22, 6:32 pm, wrote:
I have an old TPX 720 handheld radio. It was sitting for 20 + years
and the rechargable batteries were shot. They are 1.2 v nicads, 10 of
them. Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? The nicads are 12
volts total, and the dry cells would be 15. I don't want to fry the
radio.

Thanks

Kurt

Hook it up to a car battery to test it.

I rebuilt my 700 mah, 10 cell Delcom handheld radio battery pack with
new 2200 mah nimh batts. Got them from Ebay for $1 each. They are
green with solder tabs on them. So far they work very well, take the
2200mah as advertised, and power the radio for at least 12 hours. You
can get them with or without solder tabs. Be sure to check the
dimension of your AA cell before buying a replacement.

/Adam

What's your email? for the manual...

I have the same radio...bought if back in the day when it was the coolest thing out there....(and oh so compact!)

I used this as a sort of panel mount radio in two homebuilt airplanes...It's cool that you can plug in a standard aviation headset...no tiny special plugs or adapters...

I've purchased new 10 pack AA holders on the internet...


I also have a 10 battery charger for AA nickle metal hydride batteries...

Years past I ordered 10 pcs Ni cad with solder tabs and soldered up a pack.

Now I have to take the cells out of the radio to charge...since the charging jack crapped out years ago...but I still use this radio from time to time..


Cookie


On Saturday, March 22, 2008 at 7:32:40 PM UTC-4, wrote:
I have an old TPX 720 handheld radio. It was sitting for 20 + years
and the rechargable batteries were shot. They are 1.2 v nicads, 10 of
them. Before I go out and buy more, does anyone know if I can just
put regular aa cells in it to see if it works? The nicads are 12
volts total, and the dry cells would be 15. I don't want to fry the
radio.

Thanks

Kurt