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Reviews For: Diamond CP6 multi-band trap-vertical

Category: Antennas: HF: Verticals; Wire; Loop

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Review Summary For : Diamond CP6 multi-band trap-vertical
Reviews: 43MSRP: 320
Description:
The CP6 is a multi-band trap-vertical antenna for HF bands, covering the 80*, 40, 20, 15, 10 & 6m amateur bands. Made from heavy-duty aluminum, the CP6 is easily assembled, yielding excellent performance and reliability from a compact base station.
*80m CW only. SSB requires a tuner.
antenna.

This product has been discontinued.
Product is in production
More Info: http://www.rfparts.com/diamond/multi2.html
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00433.8
EB3BRJ Rating: 2008-05-26
It is OK for 15-6 m Time Owned: 3 to 6 months.
I had the CP-6 for three month now. I have to say that is very simple to put together and adjust.
performance is OK on 6, 10 and 15 meters. in 20 mt gain is way lower than my three band 20-20-40 meter inverted V with traps I made with the Unadilla traps. So I use the inverted V for the lower bands and the CP6 for 15 meters and up.
Considering the price (which is about 240 euros in Spain) I guess is and OK option.
It got me some DX contacts with the due propagation.
In 80 meters is veeeery narrow. I had to stick an extension tube at the end of the radial to be able to make it resonate on 3580 KHz for PSK31. I guess for PSK down there is useable, specially considering I have no space for a real 80 meters antenna.
M0KDB Rating: 2008-05-04
Great performance poor construction materials Time Owned: more than 12 months.
I have owned my CP-6 now for nearly three years. I bought it second hand off a friend who had only used it very briefly. This was my first vertical for Hf having previously used horizontal wire antenna's.
The antenna was easy enough to assemble when first bought although i noted that some parts seemed to be less than substantial in construction and even poor in quality.Supplied Screws were poor so replaced with stainless. The mounting for the radials was of poor quality and quite soft metals. After assembly the antenna tuned up well on all bands without an ATU i tuned for centre of each band with no problems. Using an ATU also allows me to use edges of the bands and WARC bands with no problems.
In the three years i have owned the antenna it has been taken down twice for retuning. No matter how much i seal them the radials still suffer with water getting in despite having drain holes. I have just put the antenna back up yesterday after spending two days repairing it. My initial thought that some parts were poorly constructed was correct with the radial mounting parts needing to be redrilled and tapped as the thread had worn out till some radials just fell off into my neighbours garden!!!!!!
Overall the antenna performs well across all bands but unfortunately it is let down by a poor quality of parts and workmanship and after three years this antenna is literally falling to pieces. I have remade and replaced some parts. The only thing going in its favour is that despite this it still works great although requires regular maintenance.
I do get high winds at my QTH but thought a Diamond antenna would be upto it.
G8ITB Rating: 2008-05-03
Excellent for Limited Space! Time Owned: more than 12 months.
Living in a suburban area (No CCR's - but we do have planning laws for antenna installations!)with a small narrow garden any amateur HF antenna is very visible! The CP-6 (Not 6A - that's US 75/80M coils) was mounted at the far end of the garden, 7 metres agl and fed with LMR-400, unused surplus from a new cellular telephone mast. OK - it's not a HF log periodic on a 30 metre tower; but it works well enough to get me out - much better than I initially expected! Even down to ZL at times, with just a simple 100 watts out of a TS-2000X. I also use an auto ATU (AT-300) for a long wire - that works well for Europe and eastern USA/Canada; the CP-6 gets the real DX - for me! It's small profile blends well into the background at a distance and does not upset the neighbours view. I have two friends who have put CP-6s up on the roofs of appartment houses - one in Malta and one in London. Both were only accepted because of their small profiles; anything else would have been rejected by the building owners - they work excellently for their users.
Diamond - please bring this item back into production - it works! It's far better than that 'dummy load' with a wire or element that you now market as HF antennas!

Richard G8ITB
EI5GSB Rating: 2007-10-07
Not bad at all Time Owned: 6 to 12 months.
Takes a bit to set it up for the best SWR, I'd have to recommend using an antenna analysiser, but with a bit of patience you can break that pile up.
EI5GSB
VK2TWM Rating: 2007-06-12
Awesome Antenna for the $$$$ Time Owned: 6 to 12 months.
I've had the CP6 in the air for about 12 months. I must admit I'm pretty impressed with it's performace. SWR on all bands is around 1.5:1. I live in suburban Sydney and am able to work stations from all over VK and ZL on all bands.
I have received reports of 5/9 with only the standard 100w. Also worked some European and US stations, receiving fair signals reports of 5/5 from them also.
Only problems I've found with the CP6 is that it's very narrow banded on 80m. But as I rarely work 80m. It's not a problem for me. It also picks up a fair bit of powerline noise. I guess thats to be expected from a vertical antenna in a suburban situation!
All in all! The Diamond CP6 is a great choice if you live in the burbs.
Over all it's a top performer for what it is.
73s & Happy DX VK2TWM
PE4BAS Rating: 2006-11-10
Could be better... Time Owned: more than 12 months.
I do own this antenna now for 2 years. It did a great job when it was new. But within these 2 years I had to tune it again twice for a better SWR. I live in a windy location at the coast and so unfortenatly the antenna is not standing up straigth anymore. The plastic insulation in the trap coils did become loose and I see no way to fix it.
Since one month the SWR on 40 Mtr is 1:1,5 and before it was 1:1,1 I cannot get it lower. The SWR on 15 Mtr was always best on 21.220. But now it's best is on 21.000 and whatever I do, I cannot get it back on 21.220. I did look for extreme corrosion or a faulty connection anywhere, and mine did come with stainless steel screws, but nothing faulty found. Another unfortunate thing is the 80 Mtr. Why not make a element with a good SWR exactly between the SSB and CW part of the band. This antenna is on it's best on 20 and 15 Mtr if you ask me. And overall it did a reasonable job over the past 2 years if you compare it with others. Despite of some SWR problems which are easily tuned by my antennatuner it still performs good on the desired frequencies.
VK2FAMB Rating: 2006-05-07
Great except on 80m Time Owned: 0 to 3 months.
This is my preliminary report on this antenna after putting it together, erecting it and tuning it up. This is my first attempt at installing a multiband antenna. Well boxed and packaged. Initial impressions when taken out of the carton were of extreme good quality. Easily put together with no major dramas. Instructions were easy to understand. Time taken to put together and erect on a 15 foot pole attached to the side of my house with the base of the antenna clearing the top of my roof line was 2.5 hrs. The bottom of the mast is bolted onto a 2.5" diameter copper pipe driven 2 feet into the ground.
Re-tuned the radials from specifications to resonate frequencies where mostly used around the call channels for each particular band. Excellent SWR of < 1.5 on all bands narrowing as expected towards 40 & 80 M.
Only problem I am having with 80M is that I cannot resonate up the frequency to 3.590, like I did with the other bands. The best I can get is 1.1 on 3.490 and 1.5 on 3.505.
A tuner is a MUST due to its narrow bandwith on 80 and 40, and also to tune the 80 band where needed for SSB. I use a MFJ993B auto tuner and it tunes the 80M band down to 1.2 on any part of this band having an initial SWR of >7, with no problems at all.
I have spoken interstate covering a distance of up to 1000 kilometers with it and have had excellent signal reports with each contact on 80 and 40m, considering I was only using 10 watts due to my power limitations.
I find this antenna to be a great choice especially to the newcomers like myself who is starting out in this hobby. I would have given it a 5 but due to it not resonating where i wanted to go to on 80m I give it a 4 only.
Will give another update when I have worked it for a few months.
IW0HOU Rating: 2006-01-02
Easy antenna Time Owned: 6 to 12 months.
The ideal vertical for hams with both limited space and less-than-average experience on antenna tuning.

It's well built, easy to mount and tune and very small so to be placed in almost any stable location.
Of course,as we used to say here in Italy, you can't have your wife drunk and your wine keg full... the CP6 is small so don't expect great performances on 40 m.: it's more than 1 S point below my half-windom (20 mt.) both in RX and TX.
In 80 m. it tunes well only in CW portion of the band and it's impossible to use it on frequencies >3.650 even using the auto tuner of my Mark V.
On the other bands I have no need to use the ATU (almost everywhere SWR is <1.5).

If you have space for only one HF antenna on your roof, the CP6 is the right choice. For DX or serious contest activity... you need larger antennas (also due to its very limited maximum power: 200 W p.e.p. SSB)

73, IW0HOU Alex
M1AUN Rating: 2005-09-29
M1AUN Time Owned: 0 to 3 months.
Hi hello i have owned a Diamond CP6 for around one month and found the results quite good for such a small multi band trap antenna.The instructions are a little bit vague.For some reason unable to tune 80m.80 meters is used thro a MFJ Intellituner(They are one brilliant tuner)Adjustmet of the radials real easy to tune to low V.S.W.R.All round not a bad antenna.John (M1AUN)
BU2AI Rating: 2005-02-17
Good for its price and size Time Owned: 3 to 6 months.
I have set this antenna (80m model) by myself within 3hrs in Oct, 2004; and the instruction is a little bit difficult to read. Mine is installed 15m from ground and 3m from roof, not very tall. CP6 has the advantage for its size; however, it's also it advantage for the preformance on 80m. I just simply list some thoughts I can think about below:

Pros:
1. Size: It's really good for OMs w/ limited roof space. It's not very tall and heavy either, so ok for one man to set it up.
2. Price: It's has relative low price comparing to other vertical antennas.(but no WARC band)
3. TX: Listening sides usually report good RST.
4. Adjustment: Very simple calculation and adjustment.
5. Structural Strength: Mine has experienced 2 typhoons. The gust was recorded to reach 50kts at rearby airport, and the antenna is not effected at all.
6. Stability: During the last 4 month, the SWR did not change significantly. Abt 0.15 difference at most for any single frequency.

Cons:
1. Noise: Like reviews for most verticals, it does pick up static noise easily. Not very good for hams in cities (but we are the ones with limited roof space!). It's ok if you have good RX capability on your txcr.
2. Size: It's advantage and disadvantage. It's too small on 80m; therefore, don't expect very good TX/RX performance. I did managed to complete a dx cw qso w/ Costa Rica(TI4), but it's really weak compared with it's performance on 40m(S9 on 40m and S3 on 80m, QSY to 80m on his request)
3. Fair RX: As mentioned above, CP6 is good on TX, but it's usually weak for RX(tried TS140/IC-706/PCR1K). Compared with another local station abt 2km from me using JRC txcr w/ R-5, He got most EU stations by S9, but I only have S3 (with noise floor at S2!) I was told this antenna has positive db only on 10m band, and negative db on all the other bands. My experience agree with this info. Very good signal and sound quality with VK stations when 10m is open (Almost FM quality for me).
4. Narrow bandwidth: Other than 10m band, a tuner is a must. The SWR simply can't get below 2 all the time for the entire working freq range.
5. Need ground clearance: Mine is 3m from roof. I simply can't get the SWR right(centered) for the 80m band. I was told to have at least 4.5m clearance.
6. No WARC band: It's how it is designed, so nothing to say about it.

I do recommand this antenna for OM who knows his/her needs. It performs well when the band opens. It's simple to setup, and it is strong. As about its performance, though it was said to have negative db, I do managed to break through the JA wall in couple pileups, but it takes time and patience, and the condition of that band need to be on your side.