RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Shortwave (https://www.radiobanter.com/shortwave/)
-   -   Replacing antenna for Radio Shack DX-375 (https://www.radiobanter.com/shortwave/256605-replacing-antenna-radio-shack-dx-375-a.html)

Derek Schur[_2_] April 14th 18 10:45 PM

Replacing antenna for Radio Shack DX-375
 
So I have the above listed reciever (Radio Shack DX-375) that has long
since had the built in telescopic whip antenna broken off. I'm looking
for advice in making do without. Does anyone have any advice on this,
besides simply addind a random wire in it's place?

[email protected][_2_] April 14th 18 11:01 PM

Replacing antenna for Radio Shack DX-375
 
eBay is your friend. Search on "replacement telescoping antenna". You might find an exact replacement. If not, you can solder or crimp something on stub.


Frank[_14_] April 15th 18 02:32 AM

Replacing antenna for Radio Shack DX-375
 
On Sat, 14 Apr 2018 17:45:26 -0400, Derek Schur wrote:

+AD4 So I have the above listed reciever (Radio Shack DX-375) that has long
+AD4 since had the built in telescopic whip antenna broken off. I'm looking
+AD4 for advice in making do without. Does anyone have any advice on this,
+AD4 besides simply addind a random wire in it's place?

Inexpensive generic replacement antennas are available on Ebay, if you don't mind ordering from China and waiting a couple of weeks or a month.

Maybe something like this?

https://www.ebay.com/itm/62cm-Long-4...OSwSz1an5Y+AH4

That's just an example. I haven't bought that telescopic antenna or dealt with that seller. I have Ebay'd some electronic items from China and have been very pleased.

If you're interested, do a search for +ACI-telescopic antenna+ACI and sort by Price +- Shipping:lowest first.

Be sure to double check for a suitable length and fitting on the end.


Derek Schur[_2_] April 15th 18 03:22 AM

Replacing antenna for Radio Shack DX-375
 
On Sat, 14 Apr 2018 17:45:26 -0400, Derek Schur
wrote:

So I have the above listed reciever (Radio Shack DX-375) that has long
since had the built in telescopic whip antenna broken off. I'm looking
for advice in making do without. Does anyone have any advice on this,
besides simply addind a random wire in it's place?



So, I'll add onto this. First of all, thanks to those who have
answered, so far. I'll both consider them, and leave them for others
in the same situation. What I also want to cnsider, is this. Are there
any homebrew antennas that might work on the shortwave bands, that are
worth considering, in my situation?

Frank[_14_] April 15th 18 03:38 AM

Replacing antenna for Radio Shack DX-375
 
On Sat, 14 Apr 2018 22:22:58 -0400, Derek Schur wrote:

+AD4 On Sat, 14 Apr 2018 17:45:26 -0400, Derek Schur
+AD4 +ADw-derek.s777+AEA-protonmail.com+AD4 wrote:
+AD4
+AD4APg-So I have the above listed reciever (Radio Shack DX-375) that has long
+AD4APg-since had the built in telescopic whip antenna broken off. I'm looking
+AD4APg-for advice in making do without. Does anyone have any advice on this,
+AD4APg-besides simply addind a random wire in it's place?
+AD4
+AD4
+AD4 So, I'll add onto this. First of all, thanks to those who have
+AD4 answered, so far. I'll both consider them, and leave them for others
+AD4 in the same situation. What I also want to cnsider, is this. Are there
+AD4 any homebrew antennas that might work on the shortwave bands, that are
+AD4 worth considering, in my situation?

Does your radio have a connector for an external antenna?

Derek Schur[_2_] April 15th 18 05:35 AM

Replacing antenna for Radio Shack DX-375
 
On Sun, 15 Apr 2018 02:38:53 -0000 (UTC), Frank
wrote:

On Sat, 14 Apr 2018 22:22:58 -0400, Derek Schur wrote:

On Sat, 14 Apr 2018 17:45:26 -0400, Derek Schur
wrote:

So I have the above listed reciever (Radio Shack DX-375) that has long
since had the built in telescopic whip antenna broken off. I'm looking
for advice in making do without. Does anyone have any advice on this,
besides simply addind a random wire in it's place?



So, I'll add onto this. First of all, thanks to those who have
answered, so far. I'll both consider them, and leave them for others
in the same situation. What I also want to cnsider, is this. Are there
any homebrew antennas that might work on the shortwave bands, that are
worth considering, in my situation?


Does your radio have a connector for an external antenna?


No. Amy replacement would need to attatch to where the telescope
screwed on to the base of where the telescopic antenna was attatched,
if not internally to the radio.

Frank[_14_] April 15th 18 06:13 AM

Replacing antenna for Radio Shack DX-375
 
On Sun, 15 Apr 2018 00:35:01 -0400, Derek Schur wrote:

+AD4 On Sun, 15 Apr 2018 02:38:53 -0000 (UTC), Frank +ADw-analogdial+AEA-mail.com+AD4
+AD4 wrote:
+AD4
+AD4APg-On Sat, 14 Apr 2018 22:22:58 -0400, Derek Schur wrote:
+AD4APg
+AD4APgA+ On Sat, 14 Apr 2018 17:45:26 -0400, Derek Schur
+AD4APgA+ +ADw-derek.s777+AEA-protonmail.com+AD4 wrote:
+AD4APgA+
+AD4APgA+AD4-So I have the above listed reciever (Radio Shack DX-375) that has long
+AD4APgA+AD4-since had the built in telescopic whip antenna broken off. I'm looking
+AD4APgA+AD4-for advice in making do without. Does anyone have any advice on this,
+AD4APgA+AD4-besides simply addind a random wire in it's place?
+AD4APgA+
+AD4APgA+
+AD4APgA+ So, I'll add onto this. First of all, thanks to those who have
+AD4APgA+ answered, so far. I'll both consider them, and leave them for others
+AD4APgA+ in the same situation. What I also want to cnsider, is this. Are there
+AD4APgA+ any homebrew antennas that might work on the shortwave bands, that are
+AD4APgA+ worth considering, in my situation?
+AD4APg
+AD4APg-Does your radio have a connector for an external antenna?
+AD4
+AD4 No. Amy replacement would need to attatch to where the telescope
+AD4 screwed on to the base of where the telescopic antenna was attatched,
+AD4 if not internally to the radio.

If your fabrication skills are good, you could construct a tuned loop for SW. There's plans on the web and youtube videos. I think you'd be able to get by without the coupling loop, just put the radio close to the antenna, in the right direction, and radio's internal ferrite antenna will pick it up.

The loop doesn't have to be circular.

Joe from Kokomo[_2_] April 15th 18 02:55 PM

Replacing antenna for Radio Shack DX-375
 
On 4/14/2018 10:22 PM, Derek Schur wrote:

On Sat, 14 Apr 2018 17:45:26 -0400, Derek Schur
wrote:

So I have the above listed reciever (Radio Shack DX-375) that has long
since had the built in telescopic whip antenna broken off. I'm looking
for advice in making do without. Does anyone have any advice on this,
besides simply addind a random wire in it's place?



So, I'll add onto this. First of all, thanks to those who have
answered, so far. I'll both consider them, and leave them for others
in the same situation. What I also want to cnsider, is this. Are there
any homebrew antennas that might work on the shortwave bands, that are
worth considering, in my situation?


When you say "homebrew" antenna, presumably you mean an external antenna.

If that is the case, you also say "in my situation" without going into
details of what your situation is. Residential home? Apartment? Option
to put your random wire outside?

The bottom line is your original thought of a simple random length wire
(inside or outside) connected to where the telescopic whip was connected
seems the best way for you to go...if you can accept the limitation
mentioned below.

There is no "miracle" short wave antenna that will work very much better
than the whip (to say nothing of the fact the radio was *designed* to
work with a whip). Even if you do put up a random length wire, you will
be giving up convenience. With the whip, you can use the radio anywhere,
rather than be limited to where the long wire terminates.

My vote is for what others have suggested -- search eBay/the internet
for a replacement whip.

Good luck and let us know how you make out.

George Cornelius April 15th 18 11:08 PM

Replacing antenna for Radio Shack DX-375
 
In article , Frank writes:
If your fabrication skills are good, you could construct a tuned loop for SW. There's plans on the web and youtube videos. I think you'd be able to get by without the coupling loop, just put the radio close to the antenna, in the right direction, and


The problem without having an antenna input is that you do not have
any specs for input impedance, All you know is it is almost certainly
_not_ 75 ohms.

If you think about it, a quarter wave antenna for 30 Mhz, by the hams'
rule of thumb L = 234/f, is 7.8' . It gets longer for everything else,
up to 250' or so for the broadcast band. This means a high negative
(capacitive) reactance, typically, is expected at the input circuit,
and if they were to tune some of that out with an inductor they would
see a low, resistive, source impedance feeding the RF amp stage.

That's about as far as I am able to analyze this, but I would
recommend an SWL antenna tuner, which is likely capable of adjusting
to anything from a random wire to a multielement beam. The manual
may just tell you what you need to know about feeding the receiver at
the whip antenna input point.

I'm out of touch, but I think MFJ, and maybe Ten-Tec, might have
had such tuners in the past. There may also be preselectors -
basically RF preamps - in case your receiver does not have
a high performance RF input stage.

The ARRL Handbook, and the Antenna Handbook, will both have
sections on antenna couplers. A simple L network is basically
only two components, with at least one of them being tunable.
The trick is choosing the components and their configuration,
and that's where the commercial product comes in: they've already
worked out compromise values.

After that, the actual antenna you decide on is not so important.
You can start with a random wire and move up to something more
sophisticated.

George

George Cornelius April 17th 18 09:17 AM

Replacing antenna for Radio Shack DX-375
 
In article , I wrote:
The ARRL Handbook, and the Antenna Handbook, will both have
sections on antenna couplers. A simple L network is basically
only two components, with at least one of them being tunable.
The trick is choosing the components and their configuration,
and that's where the commercial product comes in: they've already
worked out compromise values.


There is an external antenna specified in the manual, and an aBay search
for completed listings, worldwide, for a 278-1374, gives this item
(hope it's usable):

https://www.ebay.com/itm/Radio-Shack...p2047675.l2557

Note that elsewhere in the listing it gives another part number, I think
one I saw listed somewhere as a "similar item". Looks like it might just
be a clip-on, retractable, extension wire?

Price was $8.88 plus shipping from Plano, TX, a Dallas suburb near Texas
Instruments headquarters.

Also, I wrote that you might need an antenna tuner for an external
antenna, but this just seems to clip on directly, so that's a good sign.
Otherwise I was going to guess that the receiver had inductive
antenna impedance compensation, varying by band, and building just a
series capacitor substitution box that went by decade from 50pf to
50nf might compensate for that in order to work with an antenna of
design impedance of, say, 50-300 ohms.

Also, the manual I found on the web states that below 7100 Mhz, the 375
(has gap from 6250-7100), and the 396 as well, use a combination of the
whip and the internal loopstick.

George


All times are GMT +1. The time now is 12:03 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
RadioBanter.com