Hi

The GR-78 runs from internal Ni-Cad batteries charged through either
240v AC or 12v 2 pin rear sockets. I am looking for plugs to suit one or
the other. Does anyone know what the technical description of these
(other than a Heath part no) and/or a possible source of supply? It is a
nuisance to open up the set to charge the batteries!

Thanks

Simon

Hello Simon,

I presume you are talking about the DC plug. The AC (through which the
batteries ostensibly receive charging current while the radio is plugged in
is just a standard AC cheater cord type jack. The goofy polarized bladed
plug and jack were "J502" and "P502" generics. You might be able to find a
Cinch plug..from Surplus Sales of Nebraska or Fair Radio or somewhere; .not
sure of the number but it will have "502" somewhere in its nomenclature. .
Years ago I replaced the jack with a more standard jack to allow me to get
the power to the NiCd charging circuit and I no longer worry about losing
the DC cord with the oddball plug since the jack is now easily mated with a
much more standard plug. You can use anything, even an SO-239 coax jack if
you aren't concerned about convention or appearance . Also I found that
the NiCds Heath supplied were notoriously weak and would only survive,
maybe, a hundred charges. Once I seem to remember I was able to break the
internal short by supplying high current to it and "revitalize" the NiCd for
another 20 or 30 charges but that was it. I built my GR-78 in 1975 and by
the time Heath folded I had probably replaced that darned battery 3 or 4
times and it was fairly expensive as I recall. With the battery, too, I
replaced it with, I think, two 6-volt batteries in place of the internal
battery and it has worked since Heath closed its doors.

Good luck.

Vern W9STB

"Simon" wrote in message
...
Hi

The GR-78 runs from internal Ni-Cad batteries charged through either
240v AC or 12v 2 pin rear sockets. I am looking for plugs to suit one or
the other. Does anyone know what the technical description of these
(other than a Heath part no) and/or a possible source of supply? It is a
nuisance to open up the set to charge the batteries!

Thanks

Simon

Smokey wrote:
I presume you are talking about the DC plug. The AC (through which the
batteries ostensibly receive charging current while the radio is plugged in
is just a standard AC cheater cord type jack. The goofy polarized bladed
plug and jack were "J502" and "P502" generics. You might be able to find a
Cinch plug..from Surplus Sales of Nebraska or Fair Radio or somewhere; .not
sure of the number but it will have "502" somewhere in its nomenclature. .

2-pin Cinch-Jones connectors are available off the shelf from Allied
Electronics. Newark may have them too.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
Smokey wrote:
I presume you are talking about the DC plug. The AC (through which the
batteries ostensibly receive charging current while the radio is plugged in
is just a standard AC cheater cord type jack. The goofy polarized bladed
plug and jack were "J502" and "P502" generics. You might be able to find a
Cinch plug..from Surplus Sales of Nebraska or Fair Radio or somewhere; .not
sure of the number but it will have "502" somewhere in its nomenclature. .

2-pin Cinch-Jones connectors are available off the shelf from Allied
Electronics. Newark may have them too.
--scott

Thanks, Vern and Scott for your replies. As a collector of old sets, I
prefer to keep them original where possible. I had to replace the
Ni-cads with set of AAs soldered in the same format as the old Heath one
which was dead. I don't think we have cheater plugs here, but maybe
under another name. Unfortunately Cinch-Jones plugs are not available in
Australia and getting one from US suppliers is almost impossible these
days due to either anti-terrorist legislation (export permits now needed
for retail electronics) or credit card use (sorry, you have no confirmed
US address). Fortunately buying from private individual is technically
easier using Paypal but the new postage rates with no more seamail makes
boatanchor purchases uneconomic. Simon

Simon wrote:

Thanks, Vern and Scott for your replies. As a collector of old sets, I
prefer to keep them original where possible. I had to replace the
Ni-cads with set of AAs soldered in the same format as the old Heath one
which was dead. I don't think we have cheater plugs here, but maybe
under another name. Unfortunately Cinch-Jones plugs are not available in
Australia and getting one from US suppliers is almost impossible these
days due to either anti-terrorist legislation (export permits now needed
for retail electronics) or credit card use (sorry, you have no confirmed
US address). Fortunately buying from private individual is technically
easier using Paypal but the new postage rates with no more seamail makes
boatanchor purchases uneconomic. Simon

So write info at cinch dot com, and ask them who the Antipodean sales
distributor for their line is.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."