Hi

I've got 3 hot hamfest finds so far this season and need documentation
on each of them. If you have leads on datasheets or schematics I'd
appreciate hearing from you.

Here are the items:

1. A homebrew 420-450 MHz 20 watt amplifier that uses a a Motorola
"SHW158 612". A datasheet on the Motorola RF Module would help me get
it going (or at least tesed). The amp is missing 1 component (probably
a pot used to bias it).

2. A Heath HA-201A 2 meter fm amplifier. A schematic would allow me to
figure out how to re-bias this amp for linear service. Please note that
this is quite different from the HA-201 (without the "A" suffix) for
which there IS documentation at the BAMA site.

3. A Heath IB-1102 nixie based frequency counter. It's currently in
working condition but it triggers poorly at high frequencies. A
schematic / manual would allwo me to re-adjust it / modify it for more
reiable opearation at 100 MHz.

The commercial sources for documentation on the 2 Heath items are
asking very high (way more than the cost of the items themselves)
prices for the paper work.

Thanks in advance for any leads.

73,
Lenny W2BVH

" wrote:

Hi

I've got 3 hot hamfest finds so far this season and need documentation
on each of them. If you have leads on datasheets or schematics I'd
appreciate hearing from you.

Here are the items:

1. A homebrew 420-450 MHz 20 watt amplifier that uses a a Motorola
"SHW158 612". A datasheet on the Motorola RF Module would help me get
it going (or at least tesed). The amp is missing 1 component (probably
a pot used to bias it).


Motorola parts starting with "S" are proprietary marked for the OEM.
Look at MHW in similar packages to figure out which part they renumbered
for their customer. Here is a page with some basic Motorola hybrid specs
to get you started. http://www.rfparts.com/module.html


2. A Heath HA-201A 2 meter fm amplifier. A schematic would allow me to
figure out how to re-bias this amp for linear service. Please note that
this is quite different from the HA-201 (without the "A" suffix) for
which there IS documentation at the BAMA site.


Can't help with this one.


3. A Heath IB-1102 nixie based frequency counter. It's currently in
working condition but it triggers poorly at high frequencies. A
schematic / manual would allwo me to re-adjust it / modify it for more
reiable opearation at 100 MHz.


I have a schematic on the IB-1101 Nixie counter which might help.
Heath reused a lot of their designs, so the input might be close enough
to help.


The commercial sources for documentation on the 2 Heath items are
asking very high (way more than the cost of the items themselves)
prices for the paper work.

Thanks in advance for any leads.

73,
Lenny W2BVH


--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

Hi Michael,

I posted a reply earlier today, but it seems that it never hit the news
server. I aplogize if it now ends up on this thread twice!

Thanks for your reply. I was able to get info on the RF Module by
starting at the site you suggested and digging deeper into the net from
there. A very similar module is the Motorola MHW-720-1. From that data
sheet I find that the missing part(s) on my amplifier board are used to
key the first stage of the amplifier during transmit. I'll now be able
to test it out without ruining it.

I'd be pleased to reimburse you for the cost of copying and mailing the
documentation of the Heath IB-1101. If you're willing to do it please
email me: lennyw at comcast dot net. Maybe the 1101 and 1102 are
similar enough that the schematic will help.

If any other members of the newsgroup have info on the Heath IB-1102
frequency counter or the Heath HA-201A 2 meter fm amplifier, I'd
appreciate hearing from you.

Thanks again.

73,
Lenny W2BVH

In article .com,
" wrote:

2. A Heath HA-201A 2 meter fm amplifier. A schematic would allow me to
figure out how to re-bias this amp for linear service. Please note that
this is quite different from the HA-201 (without the "A" suffix) for
which there IS documentation at the BAMA site.

Lenny-

Many yers ago I had a couple of the HA-201s. They had a chronic problem
of self-oscillation, which I eventually managed to tame. I did not
remember that there was an HA-201A version, but it stands to reason.

I have a couple more of the HA-201s that I picked up at a Hamfest, but
haven't had a chance to do anything with them. I would be interested if
you find any information about the difference. As I recall, my "fix" to
the older version involved adding multiple filter capacitors across the DC
power input. Perhaps there is a better way.

73, Fred, K4DII