Scanking TXHF-6 discone for attic?

[va2fsh]

Hi! Just bought my first HF radio: A used Alinco DX-SR8. Should be a neat little radio that won't break the bank for my first foray into HF. I have no intention to put up a tower yet, so I'll have to seek an attic antenna. I have no idea how much space I have available up there.

I was looking at a Moonraker ScanKing TXHF-6 (Scanking TXHF-6 Discone 80-6m Antenna) for use in my attic...seems like a good antenna (jack of all trades) that will get me on the air. I couldn't find that many reviews though.

Has anyone on radioreference used this antenna? Comments or thoughts?

Cheers!

David VA2FSH

 

[prcguy]

Hi! Just bought my first HF radio: A used Alinco DX-SR8. Should be a neat little radio that won't break the bank for my first foray into HF. I have no intention to put up a tower yet, so I'll have to seek an attic antenna. I have no idea how much space I have available up there.

I was looking at a Moonraker ScanKing TXHF-6 (Scanking TXHF-6 Discone 80-6m Antenna) for use in my attic...seems like a good antenna (jack of all trades) that will get me on the air. I couldn't find that many reviews though.

Has anyone on radioreference used this antenna? Comments or thoughts?

Cheers!

David VA2FSH

Don't do it. That antenna is not a Jack of any trade and I'll bet nobody will hear you outside your immediate neighborhood.

 

[va2fsh]

Really? I'd like to understand the reasoning behind your statements so I can better evaluate antennas in the future. Care to provide more details?

Appreciate it!
David

 

[prcguy]

Really? I'd like to understand the reasoning behind your statements so I can better evaluate antennas in the future. Care to provide more details?

Appreciate it!
David

Just for reference, a half wave dipole on 80m is 133ft long and on 40m its about 65ft long. A full size dipole is a very good antenna if you have the space and there are smaller antennas that can work ok.

However, the TXHF has a tiny, I mean miniscule little loading coil for each band working against a wholly inadequate ground plane or counterpoise, even by 10m standards. I would estimate radiation efficiency on 80m to be 1% at best and not much better on 40m.

Trying to use this antenna on any HF band is not much different than having a new 100w per channel stereo amplifier and you bought two tiny speakers with 1" diameter cones and expect room filling sound. There is nothing but disappointment waiting for you if you buy that antenna.

 

[va2fsh]

I get your point. Seems legit: It's physics (tm), right?

What I don't understand though is:
1) How can they sell such an antenna if it's wholly inadequate for the intented purpose
2) How were reviewers able to use it successfully? I mean, physics are physics and if my neighbors down the street shouldn't be able to hear them...how come they can?

Still being the HF newbie that I am, what other options are there for a multi-band attic antenna that's relatively compact and can both receive and transmit on 80-6m (let's say 80-10m, cause I don't even think my DX-SR8 can do 6m)? I'd like to be able to purchase a working antenna as I don't have the knowledge or equipment to build and tune one yet. I'd ideally want to spend at most, the price I paid for the radio on the antenna: 280$ CAD.

I'm finding all kinds of various antennas, but all are massive and need to be put outside on a tower.

David

 

[prcguy]

I get your point. Seems legit: It's physics (tm), right?

What I don't understand though is:
1) How can they sell such an antenna if it's wholly inadequate for the intented purpose
2) How were reviewers able to use it successfully? I mean, physics are physics and if my neighbors down the street shouldn't be able to hear them...how come they can?

Still being the HF newbie that I am, what other options are there for a multi-band attic antenna that's relatively compact and can both receive and transmit on 80-6m (let's say 80-10m, cause I don't even think my DX-SR8 can do 6m)? I'd like to be able to purchase a working antenna as I don't have the knowledge or equipment to build and tune one yet. I'd ideally want to spend at most, the price I paid for the radio on the antenna: 280$ CAD.

I'm finding all kinds of various antennas, but all are massive and need to be put outside on a tower.

David

Unfortunately the antenna business is full of companies that either have no clue how to design or build an antenna, or they do and they don't. Then they post their own reviews or have friends do it to make antenna sales, that's what its all about is sales for them. We as consumers have to wade through all the lies and scams and try to see the truth to avoid making a bad purchase. Not everyone is up on antennas so sometimes you must rely on friends with experience to help you avoid a bad purchase. That's what we're here for.

 

[va2fsh]

So again, based upon my criterias, any antennas you would recommend?

David

 

[prcguy]

So again, based upon my criterias, any antennas you would recommend?

David

Does it have to go in the attic? If so how tall is the attic, how much space around an antenna can you have?

 

[prcguy]

Assuming the attic has a spot 6 or 8ft tall, about the best I can think of would be a higher end HF screwdriver antenna over a large ground plane made of chicken wire stapled over the attic floor. If you can cover at least the area of a room with chicken wire and plant the screwdriver in the center, and your roofing material is transparent to RF you can put out a better signal than the same antenna on a vehicle.

You can also cheat a bit on the top whip by using a short piece of vertical wire above the coil the a capacity hat on top made of wire that goes maybe 6ft either side of the vertical wire in the shape of a T. An HF screwdriver typically has a 6ft whip on top and with just a 1ft vertical wire and large capacity hat you can equal or exceed the performance in a much shorter package. If you go really big on the capacity hat the lower bands will perk way up at the expense of loosing a higher band or two like 10m or 15m.

If you lived in the equivalent of a log cabin with no HVAC ducting or wiring in the attic you could possibly run a shortened dipole but most houses have lots of metal stuff in the attic. The vertical HF screwdriver over ground plane will usually play nice around horizontal runs of ducting and wiring.

BTW, when I say higher end HF screwdriver I mean a big Tarheel, High Q, Scorpion, etc, and not a Yaesu or similar.

 

[W4AXW]

I have no intention to put up a tower yet, so I'll have to seek an attic antenna. I have no idea how much space I have available up there.

A tower is by no means required to operate successfully on HF, there are plenty of operators working the world on wire antennas. If whatever antenna you choose must go in the attic, it might be time to ascertain the dimensions you have to work with.

Knowledge about antenna physics will protect you from the "scam" antennas out there.

7 3

 

[va2fsh]

Hey prcguy, w4axw! Hmm, I haven't been in the attic yet. I have to muster the courage to go check to see what I'm working with in terms of space.
My roof is standard shingle and wooden trusses.

 

[prcguy]

Hey prcguy, w4axw! Hmm, I haven't been in the attic yet. I have to muster the courage to go check to see what I'm working with in terms of space.
My roof is standard shingle and wooden trusses.

If you have 7 or 8ft of vertical space at the peak you could experiment with a 20m or 40m Hamstick over a large chicken wire ground plane. That would be cheap to try out and let you know if the performance meets your expectations. Once the ground plane is in you can plant any antenna that will fit and as I mentioned the top whip on most mobile antennas can be replaced with a capacity hat made of wire shrinking its vertical size without loosing efficiency.

 

[ramal121]

So this is about an antenna. From the title I thought it had something to do with scanks. Shame on me.

 

[prcguy]

So this is about an antenna. From the title I thought it had something to do with scanks. Shame on me.

What? Whaa? Somebody calling me?? Hello???

 

[ramal121]

Alex, I'd like to buy a hyphen please.

 

[AK9R]

Alex, I'd like to buy a hyphen please.

A reminder that buying or selling is to be done in the Classifieds section.

Sadly, I don't see any hyphens listed.

 

[popnokick]

Could you do this in your attic?
Roof Mount for BBTD Cable? (click to see the diagram)

 

[Engine104]

Do you have restrictions that would prohibit an outside antenna? That would work better than one in the attic. If you have to go with an attic mount, I'd suggest a short dipole, such as a G5RV-Jr. I run one outside that is only about 20' up in the center and it works well for me. I know higher is better, but I have restrictions.

 

[WA8ZTZ]

If you absolutely must put the antenna in the attic, look into a multi-band trap dipole.
Unless your attic is very small, you should be able to find something that covers
at least 40 and up. Forget about 6, your radio doesn't do 6.
The DX-SR8 is a lot of bang for the buck, but you want (need) a good antenna.
Hy Power Antenna makes a 40 and 10 dipole that is only 33' long.
btw... you sound a bit nervous about going up into the attic... just be careful and move slowly,
take a good flashlight or better yet a headlamp, if you have blown in insulation and
cannot see the joists... forget about it.

 

[va2fsh]

Well, obviously when I started this thread I had no knowledge of HF antennas. So I did plenty of reading and I have a little clearer idea now how HF antennas work (not an expert by any stretch of the imagination!).

I'm going to give a try to having an outside antenna (EFHW slopper). It'll go from the 2nd story window towards the trees in the back of our property.

popnokick: Very interesting! In case of bad weather, I'd like to have an indoor antenna too so I'll have to check it out. Sounds like a great idea.

My attic does have blown in insulation, but I can see the joist no problem. I did go up in the attic and I seem to have approx. 10-12' high at the apex, and about 24' wide by 26' deep.

David